Local variable referenced before assignment in Python
![unboundlocalerror local variable 'db' referenced before assignment avatar](https://bobbyhadz.com/images/global/avatar.webp)
Last updated: Apr 8, 2024 Reading time · 4 min
![unboundlocalerror local variable 'db' referenced before assignment banner](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/banner.webp)
![](http://farmaciacoslada.online/777/templates/cheerup1/res/banner1.gif)
# Local variable referenced before assignment in Python
The Python "UnboundLocalError: Local variable referenced before assignment" occurs when we reference a local variable before assigning a value to it in a function.
To solve the error, mark the variable as global in the function definition, e.g. global my_var .
![unboundlocalerror local variable 'db' referenced before assignment unboundlocalerror local variable name referenced before assignment](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/unboundlocalerror-local-variable-name-referenced-before-assignment.webp)
Here is an example of how the error occurs.
We assign a value to the name variable in the function.
# Mark the variable as global to solve the error
To solve the error, mark the variable as global in your function definition.
![unboundlocalerror local variable 'db' referenced before assignment mark variable as global](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/mark-variable-as-global.webp)
If a variable is assigned a value in a function's body, it is a local variable unless explicitly declared as global .
# Local variables shadow global ones with the same name
You could reference the global name variable from inside the function but if you assign a value to the variable in the function's body, the local variable shadows the global one.
![unboundlocalerror local variable 'db' referenced before assignment accessing global variables in functions](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/accessing-global-variables-in-functions.webp)
Accessing the name variable in the function is perfectly fine.
On the other hand, variables declared in a function cannot be accessed from the global scope.
![unboundlocalerror local variable 'db' referenced before assignment variables declared in function cannot be accessed in global scope](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/variables-declared-in-function-cannot-be-accessed-in-global-scope.webp)
The name variable is declared in the function, so trying to access it from outside causes an error.
Make sure you don't try to access the variable before using the global keyword, otherwise, you'd get the SyntaxError: name 'X' is used prior to global declaration error.
# Returning a value from the function instead
An alternative solution to using the global keyword is to return a value from the function and use the value to reassign the global variable.
![unboundlocalerror local variable 'db' referenced before assignment return value from the function](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/return-value-from-the-function.webp)
We simply return the value that we eventually use to assign to the name global variable.
# Passing the global variable as an argument to the function
You should also consider passing the global variable as an argument to the function.
![unboundlocalerror local variable 'db' referenced before assignment pass global variable as argument to function](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/pass-global-variable-as-argument-to-function.webp)
We passed the name global variable as an argument to the function.
If we assign a value to a variable in a function, the variable is assumed to be local unless explicitly declared as global .
# Assigning a value to a local variable from an outer scope
If you have a nested function and are trying to assign a value to the local variables from the outer function, use the nonlocal keyword.
![unboundlocalerror local variable 'db' referenced before assignment assign value to local variable from outer scope](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/assign-value-to-local-variable-from-outer-scope.webp)
The nonlocal keyword allows us to work with the local variables of enclosing functions.
Had we not used the nonlocal statement, the call to the print() function would have returned an empty string.
![unboundlocalerror local variable 'db' referenced before assignment not using nonlocal prints empty string](https://bobbyhadz.com/images/blog/python-unboundlocalerror-local-variable-name-referenced-before-assignment/not-using-nonlocal-prints-empty-string.webp)
Printing the message variable on the last line of the function shows an empty string because the inner() function has its own scope.
Changing the value of the variable in the inner scope is not possible unless we use the nonlocal keyword.
Instead, the message variable in the inner function simply shadows the variable with the same name from the outer scope.
# Discussion
As shown in this section of the documentation, when you assign a value to a variable inside a function, the variable:
- Becomes local to the scope.
- Shadows any variables from the outer scope that have the same name.
The last line in the example function assigns a value to the name variable, marking it as a local variable and shadowing the name variable from the outer scope.
At the time the print(name) line runs, the name variable is not yet initialized, which causes the error.
The most intuitive way to solve the error is to use the global keyword.
The global keyword is used to indicate to Python that we are actually modifying the value of the name variable from the outer scope.
- If a variable is only referenced inside a function, it is implicitly global.
- If a variable is assigned a value inside a function's body, it is assumed to be local, unless explicitly marked as global .
If you want to read more about why this error occurs, check out [this section] ( this section ) of the docs.
# Additional Resources
You can learn more about the related topics by checking out the following tutorials:
- SyntaxError: name 'X' is used prior to global declaration
![unboundlocalerror local variable 'db' referenced before assignment book cover](https://bobbyhadz.com/images/global/book-cover.webp)
Borislav Hadzhiev
Web Developer
![unboundlocalerror local variable 'db' referenced before assignment buy me a coffee](https://bobbyhadz.com/images/global/sidebar-book-small.webp)
Copyright © 2024 Borislav Hadzhiev
How to fix UnboundLocalError: local variable 'x' referenced before assignment in Python
![unboundlocalerror local variable 'db' referenced before assignment unboundlocalerror local variable 'db' referenced before assignment](https://sebhastian.com/local-variable-referenced-before-assignment/cover_image.png?ezimgfmt=ng%3Awebp%2Fngcb14%2Frs%3Adevice%2Frscb15-1)
You could also see this error when you forget to pass the variable as an argument to your function.
How to reproduce this error
How to fix this error.
I hope this tutorial is useful. See you in other tutorials.
Take your skills to the next level ⚡️
[SOLVED] Local Variable Referenced Before Assignment
![unboundlocalerror local variable 'db' referenced before assignment local variable referenced before assignment](https://www.pythonpool.com/wp-content/uploads/2022/04/Local-Variable-Referenced-Before-Assignment.webp)
Python treats variables referenced only inside a function as global variables. Any variable assigned to a function’s body is assumed to be a local variable unless explicitly declared as global.
Why Does This Error Occur?
Unboundlocalerror: local variable referenced before assignment occurs when a variable is used before its created. Python does not have the concept of variable declarations. Hence it searches for the variable whenever used. When not found, it throws the error.
Before we hop into the solutions, let’s have a look at what is the global and local variables.
Local Variable Declarations vs. Global Variable Declarations
Local Variables | Global Variables |
---|---|
A variable is declared primarily within a Python function. | Global variables are in the global scope, outside a function. |
A local variable is created when the function is called and destroyed when the execution is finished. | A Variable is created upon execution and exists in memory till the program stops. |
Local Variables can only be accessed within their own function. | All functions of the program can access global variables. |
Local variables are immune to changes in the global scope. Thereby being more secure. | Global Variables are less safer from manipulation as they are accessible in the global scope. |
![unboundlocalerror local variable 'db' referenced before assignment [Fixed] typeerror can’t compare datetime.datetime to datetime.date](https://www.pythonpool.com/wp-content/uploads/2024/01/typeerror-cant-compare-datetime.datetime-to-datetime.date_-300x157.webp)
Local Variable Referenced Before Assignment Error with Explanation
Try these examples yourself using our Online Compiler.
Let’s look at the following function:
![unboundlocalerror local variable 'db' referenced before assignment Local Variable Referenced Before Assignment Error](https://www.pythonpool.com/wp-content/uploads/2022/04/image.png)
Explanation
The variable myVar has been assigned a value twice. Once before the declaration of myFunction and within myFunction itself.
Using Global Variables
Passing the variable as global allows the function to recognize the variable outside the function.
Create Functions that Take in Parameters
Instead of initializing myVar as a global or local variable, it can be passed to the function as a parameter. This removes the need to create a variable in memory.
UnboundLocalError: local variable ‘DISTRO_NAME’
This error may occur when trying to launch the Anaconda Navigator in Linux Systems.
Upon launching Anaconda Navigator, the opening screen freezes and doesn’t proceed to load.
Try and update your Anaconda Navigator with the following command.
If solution one doesn’t work, you have to edit a file located at
After finding and opening the Python file, make the following changes:
In the function on line 159, simply add the line:
DISTRO_NAME = None
Save the file and re-launch Anaconda Navigator.
DJANGO – Local Variable Referenced Before Assignment [Form]
The program takes information from a form filled out by a user. Accordingly, an email is sent using the information.
Upon running you get the following error:
We have created a class myForm that creates instances of Django forms. It extracts the user’s name, email, and message to be sent.
A function GetContact is created to use the information from the Django form and produce an email. It takes one request parameter. Prior to sending the email, the function verifies the validity of the form. Upon True , .get() function is passed to fetch the name, email, and message. Finally, the email sent via the send_mail function
Why does the error occur?
We are initializing form under the if request.method == “POST” condition statement. Using the GET request, our variable form doesn’t get defined.
Local variable Referenced before assignment but it is global
This is a common error that happens when we don’t provide a value to a variable and reference it. This can happen with local variables. Global variables can’t be assigned.
This error message is raised when a variable is referenced before it has been assigned a value within the local scope of a function, even though it is a global variable.
Here’s an example to help illustrate the problem:
In this example, x is a global variable that is defined outside of the function my_func(). However, when we try to print the value of x inside the function, we get a UnboundLocalError with the message “local variable ‘x’ referenced before assignment”.
This is because the += operator implicitly creates a local variable within the function’s scope, which shadows the global variable of the same name. Since we’re trying to access the value of x before it’s been assigned a value within the local scope, the interpreter raises an error.
To fix this, you can use the global keyword to explicitly refer to the global variable within the function’s scope:
However, in the above example, the global keyword tells Python that we want to modify the value of the global variable x, rather than creating a new local variable. This allows us to access and modify the global variable within the function’s scope, without causing any errors.
Local variable ‘version’ referenced before assignment ubuntu-drivers
This error occurs with Ubuntu version drivers. To solve this error, you can re-specify the version information and give a split as 2 –
Here, p_name means package name.
With the help of the threading module, you can avoid using global variables in multi-threading. Make sure you lock and release your threads correctly to avoid the race condition.
When a variable that is created locally is called before assigning, it results in Unbound Local Error in Python. The interpreter can’t track the variable.
Therefore, we have examined the local variable referenced before the assignment Exception in Python. The differences between a local and global variable declaration have been explained, and multiple solutions regarding the issue have been provided.
Trending Python Articles
![unboundlocalerror local variable 'db' referenced before assignment [Fixed] nameerror: name Unicode is not defined](https://www.pythonpool.com/wp-content/uploads/2024/01/Fixed-nameerror-name-Unicode-is-not-defined-300x157.webp)
![unboundlocalerror local variable 'db' referenced before assignment The Research Scientist Pod](https://researchdatapod.com/wp-content/uploads/2020/10/logo_transparent_background.png)
Python UnboundLocalError: local variable referenced before assignment
by Suf | Programming , Python , Tips
If you try to reference a local variable before assigning a value to it within the body of a function, you will encounter the UnboundLocalError: local variable referenced before assignment.
The preferable way to solve this error is to pass parameters to your function, for example:
Alternatively, you can declare the variable as global to access it while inside a function. For example,
This tutorial will go through the error in detail and how to solve it with code examples .
Table of contents
What is scope in python, unboundlocalerror: local variable referenced before assignment, solution #1: passing parameters to the function, solution #2: use global keyword, solution #1: include else statement, solution #2: use global keyword.
Scope refers to a variable being only available inside the region where it was created. A variable created inside a function belongs to the local scope of that function, and we can only use that variable inside that function.
A variable created in the main body of the Python code is a global variable and belongs to the global scope. Global variables are available within any scope, global and local.
UnboundLocalError occurs when we try to modify a variable defined as local before creating it. If we only need to read a variable within a function, we can do so without using the global keyword. Consider the following example that demonstrates a variable var created with global scope and accessed from test_func :
If we try to assign a value to var within test_func , the Python interpreter will raise the UnboundLocalError:
This error occurs because when we make an assignment to a variable in a scope, that variable becomes local to that scope and overrides any variable with the same name in the global or outer scope.
var +=1 is similar to var = var + 1 , therefore the Python interpreter should first read var , perform the addition and assign the value back to var .
var is a variable local to test_func , so the variable is read or referenced before we have assigned it. As a result, the Python interpreter raises the UnboundLocalError.
Example #1: Accessing a Local Variable
Let’s look at an example where we define a global variable number. We will use the increment_func to increase the numerical value of number by 1.
Let’s run the code to see what happens:
The error occurs because we tried to read a local variable before assigning a value to it.
We can solve this error by passing a parameter to increment_func . This solution is the preferred approach. Typically Python developers avoid declaring global variables unless they are necessary. Let’s look at the revised code:
We have assigned a value to number and passed it to the increment_func , which will resolve the UnboundLocalError. Let’s run the code to see the result:
We successfully printed the value to the console.
We also can solve this error by using the global keyword. The global statement tells the Python interpreter that inside increment_func , the variable number is a global variable even if we assign to it in increment_func . Let’s look at the revised code:
Let’s run the code to see the result:
Example #2: Function with if-elif statements
Let’s look at an example where we collect a score from a player of a game to rank their level of expertise. The variable we will use is called score and the calculate_level function takes in score as a parameter and returns a string containing the player’s level .
In the above code, we have a series of if-elif statements for assigning a string to the level variable. Let’s run the code to see what happens:
The error occurs because we input a score equal to 40 . The conditional statements in the function do not account for a value below 55 , therefore when we call the calculate_level function, Python will attempt to return level without any value assigned to it.
We can solve this error by completing the set of conditions with an else statement. The else statement will provide an assignment to level for all scores lower than 55 . Let’s look at the revised code:
In the above code, all scores below 55 are given the beginner level. Let’s run the code to see what happens:
We can also create a global variable level and then use the global keyword inside calculate_level . Using the global keyword will ensure that the variable is available in the local scope of the calculate_level function. Let’s look at the revised code.
In the above code, we put the global statement inside the function and at the beginning. Note that the “default” value of level is beginner and we do not include the else statement in the function. Let’s run the code to see the result:
Congratulations on reading to the end of this tutorial! The UnboundLocalError: local variable referenced before assignment occurs when you try to reference a local variable before assigning a value to it. Preferably, you can solve this error by passing parameters to your function. Alternatively, you can use the global keyword.
If you have if-elif statements in your code where you assign a value to a local variable and do not account for all outcomes, you may encounter this error. In which case, you must include an else statement to account for the missing outcome.
For further reading on Python code blocks and structure, go to the article: How to Solve Python IndentationError: unindent does not match any outer indentation level .
Go to the online courses page on Python to learn more about Python for data science and machine learning.
Have fun and happy researching!
Share this:
- Click to share on Facebook (Opens in new window)
- Click to share on LinkedIn (Opens in new window)
- Click to share on Reddit (Opens in new window)
- Click to share on Pinterest (Opens in new window)
- Click to share on Telegram (Opens in new window)
- Click to share on WhatsApp (Opens in new window)
- Click to share on Twitter (Opens in new window)
- Click to share on Tumblr (Opens in new window)
- Python Basics
- Interview Questions
- Python Quiz
- Popular Packages
- Python Projects
- Practice Python
- AI With Python
- Learn Python3
- Python Automation
- Python Web Dev
- DSA with Python
- Python OOPs
- Dictionaries
UnboundLocalError Local variable Referenced Before Assignment in Python
Handling errors is an integral part of writing robust and reliable Python code. One common stumbling block that developers often encounter is the “UnboundLocalError” raised within a try-except block. This error can be perplexing for those unfamiliar with its nuances but fear not – in this article, we will delve into the intricacies of the UnboundLocalError and provide a comprehensive guide on how to effectively use try-except statements to resolve it.
What is UnboundLocalError Local variable Referenced Before Assignment in Python?
The UnboundLocalError occurs when a local variable is referenced before it has been assigned a value within a function or method. This error typically surfaces when utilizing try-except blocks to handle exceptions, creating a puzzle for developers trying to comprehend its origins and find a solution.
Why does UnboundLocalError: Local variable Referenced Before Assignment Occur?
below, are the reasons of occurring “Unboundlocalerror: Try Except Statements” in Python :
Variable Assignment Inside Try Block
Reassigning a global variable inside except block.
- Accessing a Variable Defined Inside an If Block
In the below code, example_function attempts to execute some_operation within a try-except block. If an exception occurs, it prints an error message. However, if no exception occurs, it prints the value of the variable result outside the try block, leading to an UnboundLocalError since result might not be defined if an exception was caught.
In below code , modify_global function attempts to increment the global variable global_var within a try block, but it raises an UnboundLocalError. This error occurs because the function treats global_var as a local variable due to the assignment operation within the try block.
Solution for UnboundLocalError Local variable Referenced Before Assignment
Below, are the approaches to solve “Unboundlocalerror: Try Except Statements”.
![](http://farmaciacoslada.online/777/templates/cheerup1/res/banner1.gif)
Initialize Variables Outside the Try Block
Avoid reassignment of global variables.
In modification to the example_function is correct. Initializing the variable result before the try block ensures that it exists even if an exception occurs within the try block. This helps prevent UnboundLocalError when trying to access result in the print statement outside the try block.
Below, code calculates a new value ( local_var ) based on the global variable and then prints both the local and global variables separately. It demonstrates that the global variable is accessed directly without being reassigned within the function.
In conclusion , To fix “UnboundLocalError” related to try-except statements, ensure that variables used within the try block are initialized before the try block starts. This can be achieved by declaring the variables with default values or assigning them None outside the try block. Additionally, when modifying global variables within a try block, use the `global` keyword to explicitly declare them.
Please Login to comment...
Similar reads.
- Python Programs
- Python Errors
Improve your Coding Skills with Practice
What kind of Experience do you want to share?
Explore your training options in 10 minutes Get Started
- Graduate Stories
- Partner Spotlights
- Bootcamp Prep
- Bootcamp Admissions
- University Bootcamps
- Coding Tools
- Software Engineering
- Web Development
- Data Science
- Tech Guides
- Tech Resources
- Career Advice
- Online Learning
- Internships
- Apprenticeships
- Tech Salaries
- Associate Degree
- Bachelor's Degree
- Master's Degree
- University Admissions
- Best Schools
- Certifications
- Bootcamp Financing
- Higher Ed Financing
- Scholarships
- Financial Aid
- Best Coding Bootcamps
- Best Online Bootcamps
- Best Web Design Bootcamps
- Best Data Science Bootcamps
- Best Technology Sales Bootcamps
- Best Data Analytics Bootcamps
- Best Cybersecurity Bootcamps
- Best Digital Marketing Bootcamps
- Los Angeles
- San Francisco
- Browse All Locations
- Digital Marketing
- Machine Learning
- See All Subjects
- Bootcamps 101
- Full-Stack Development
- Career Changes
- View all Career Discussions
- Mobile App Development
- Cybersecurity
- Product Management
- UX/UI Design
- What is a Coding Bootcamp?
- Are Coding Bootcamps Worth It?
- How to Choose a Coding Bootcamp
- Best Online Coding Bootcamps and Courses
- Best Free Bootcamps and Coding Training
- Coding Bootcamp vs. Community College
- Coding Bootcamp vs. Self-Learning
- Bootcamps vs. Certifications: Compared
- What Is a Coding Bootcamp Job Guarantee?
- How to Pay for Coding Bootcamp
- Ultimate Guide to Coding Bootcamp Loans
- Best Coding Bootcamp Scholarships and Grants
- Education Stipends for Coding Bootcamps
- Get Your Coding Bootcamp Sponsored by Your Employer
- GI Bill and Coding Bootcamps
- Tech Intevriews
- Our Enterprise Solution
- Connect With Us
- Publication
- Reskill America
- Partner With Us
![unboundlocalerror local variable 'db' referenced before assignment Career Karma](https://careerkarma.com/blog/wp-content/uploads/2023/07/logo-circle.png)
- Resource Center
- Bachelor’s Degree
- Master’s Degree
Python local variable referenced before assignment Solution
When you start introducing functions into your code, you’re bound to encounter an UnboundLocalError at some point. This error is raised when you try to use a variable before it has been assigned in the local context .
In this guide, we talk about what this error means and why it is raised. We walk through an example of this error in action to help you understand how you can solve it.
Find your bootcamp match
What is unboundlocalerror: local variable referenced before assignment.
Trying to assign a value to a variable that does not have local scope can result in this error:
Python has a simple rule to determine the scope of a variable. If a variable is assigned in a function , that variable is local. This is because it is assumed that when you define a variable inside a function you only need to access it inside that function.
There are two variable scopes in Python: local and global. Global variables are accessible throughout an entire program; local variables are only accessible within the function in which they are originally defined.
Let’s take a look at how to solve this error.
An Example Scenario
We’re going to write a program that calculates the grade a student has earned in class.
We start by declaring two variables:
These variables store the numerical and letter grades a student has earned, respectively. By default, the value of “letter” is “F”. Next, we write a function that calculates a student’s letter grade based on their numerical grade using an “if” statement :
Finally, we call our function:
This line of code prints out the value returned by the calculate_grade() function to the console. We pass through one parameter into our function: numerical. This is the numerical value of the grade a student has earned.
Let’s run our code and see what happens:
An error has been raised.
The Solution
Our code returns an error because we reference “letter” before we assign it.
We have set the value of “numerical” to 42. Our if statement does not set a value for any grade over 50. This means that when we call our calculate_grade() function, our return statement does not know the value to which we are referring.
We do define “letter” at the start of our program. However, we define it in the global context. Python treats “return letter” as trying to return a local variable called “letter”, not a global variable.
We solve this problem in two ways. First, we can add an else statement to our code. This ensures we declare “letter” before we try to return it:
Let’s try to run our code again:
Our code successfully prints out the student’s grade.
If you are using an “if” statement where you declare a variable, you should make sure there is an “else” statement in place. This will make sure that even if none of your if statements evaluate to True, you can still set a value for the variable with which you are going to work.
Alternatively, we could use the “global” keyword to make our global keyword available in the local context in our calculate_grade() function. However, this approach is likely to lead to more confusing code and other issues. In general, variables should not be declared using “global” unless absolutely necessary . Your first, and main, port of call should always be to make sure that a variable is correctly defined.
In the example above, for instance, we did not check that the variable “letter” was defined in all use cases.
That’s it! We have fixed the local variable error in our code.
The UnboundLocalError: local variable referenced before assignment error is raised when you try to assign a value to a local variable before it has been declared. You can solve this error by ensuring that a local variable is declared before you assign it a value.
Now you’re ready to solve UnboundLocalError Python errors like a professional developer !
About us: Career Karma is a platform designed to help job seekers find, research, and connect with job training programs to advance their careers. Learn about the CK publication .
What's Next?
![unboundlocalerror local variable 'db' referenced before assignment icon_10](https://careerkarma.com/blog/wp-content/uploads/2020/05/get-matched-icon.png)
Get matched with top bootcamps
Ask a question to our community, take our careers quiz.
![unboundlocalerror local variable 'db' referenced before assignment James Gallagher](https://careerkarma.com/blog/wp-content/uploads/2020/01/james-gallagher-300x300.jpg)
Leave a Reply Cancel reply
Your email address will not be published. Required fields are marked *
![unboundlocalerror local variable 'db' referenced before assignment Apply to top tech training programs in one click](https://careerkarma.com/blog/wp-content/uploads/2022/08/sidebar-bootcamp-img.png)
How to Fix Local Variable Referenced Before Assignment Error in Python
![unboundlocalerror local variable 'db' referenced before assignment How to Fix Local Variable Referenced Before Assignment Error in Python](https://sabe.io/blog/python-local-variable-referenced-before-assignment/hero.png)
Table of Contents
Fixing local variable referenced before assignment error.
In Python , when you try to reference a variable that hasn't yet been given a value (assigned), it will throw an error.
That error will look like this:
In this post, we'll see examples of what causes this and how to fix it.
Let's begin by looking at an example of this error:
If you run this code, you'll get
The issue is that in this line:
We are defining a local variable called value and then trying to use it before it has been assigned a value, instead of using the variable that we defined in the first line.
If we want to refer the variable that was defined in the first line, we can make use of the global keyword.
The global keyword is used to refer to a variable that is defined outside of a function.
Let's look at how using global can fix our issue here:
Global variables have global scope, so you can referenced them anywhere in your code, thus avoiding the error.
If you run this code, you'll get this output:
In this post, we learned at how to avoid the local variable referenced before assignment error in Python.
The error stems from trying to refer to a variable without an assigned value, so either make use of a global variable using the global keyword, or assign the variable a value before using it.
Thanks for reading!
![unboundlocalerror local variable 'db' referenced before assignment](https://sabe.io/tutorials/php-dependencies/hero.png)
- Privacy Policy
- Terms of Service
![unboundlocalerror local variable 'db' referenced before assignment w3docs logo](https://www.w3docs.com/build/images/logo-color-w3.png)
- Password Generator
- HTML Editor
- HTML Encoder
- JSON Beautifier
- CSS Beautifier
- Markdown Convertor
- Find the Closest Tailwind CSS Color
- Phrase encrypt / decrypt
- Browser Feature Detection
- Number convertor
- CSS Maker text shadow
- CSS Maker Text Rotation
- CSS Maker Out Line
- CSS Maker RGB Shadow
- CSS Maker Transform
- CSS Maker Font Face
- Color Picker
- Colors CMYK
- Color mixer
- Color Converter
- Color Contrast Analyzer
- Color Gradient
- String Length Calculator
- MD5 Hash Generator
- Sha256 Hash Generator
- String Reverse
- URL Encoder
- URL Decoder
- Base 64 Encoder
- Base 64 Decoder
- Extra Spaces Remover
- String to Lowercase
- String to Uppercase
- Word Count Calculator
- Empty Lines Remover
- HTML Tags Remover
- Binary to Hex
- Hex to Binary
- Rot13 Transform on a String
- String to Binary
- Duplicate Lines Remover
Python 3: UnboundLocalError: local variable referenced before assignment
This error occurs when you are trying to access a variable before it has been assigned a value. Here is an example of a code snippet that would raise this error:
Watch a video course Python - The Practical Guide
The error message will be:
In this example, the variable x is being accessed before it is assigned a value, which is causing the error. To fix this, you can either move the assignment of the variable x before the print statement, or give it an initial value before the print statement.
Both will work without any error.
Related Resources
- Using global variables in a function
- "Least Astonishment" and the Mutable Default Argument
- Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3?
- HTML Basics
- Javascript Basics
- TypeScript Basics
- React Basics
- Angular Basics
- Sass Basics
- Vue.js Basics
- Python Basics
- Java Basics
- NodeJS Basics
Stack Exchange Network
Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
PGRouting Layer plugin "UnboundLocalError: local variable 'db' referenced before assignment"
I am trying to do some basic computations using the PGRouting plugin for QGIS, but I am getting this error all time:
I made a local installation of postgres 9.3.4, later I added postgis using the stack builder, and finally I followed the instructions posted here: PGRouting 2.0 for windows . I also installed python-psycopg2 for my version of python.
The SQL query runs well in pgAdminIII, but I can not make that QGIS plugin work.
- unboundlocalerror
- 1 I have seen this kind of error at the different post. Could you check the user name and password are saved at creating connection time ? gis.stackexchange.com/questions/87111/… – sanak Commented Apr 8, 2014 at 5:00
- Dear sanak, your answer has solved my problem. Thank you so much. – gtapko Commented Apr 8, 2014 at 5:24
In order to make the plugin work, I needed to save both my username and password on the database connection.
Your Answer
Sign up or log in, post as a guest.
Required, but never shown
By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .
Not the answer you're looking for? Browse other questions tagged pgrouting qgis-2 unboundlocalerror or ask your own question .
- The Overflow Blog
- How to bridge the gap between Web2 skills and Web3 workflows
- Featured on Meta
- Upcoming initiatives on Stack Overflow and across the Stack Exchange network...
- Announcing a change to the data-dump process
Hot Network Questions
- Is this circuit safe to put in my ceiling? What improvements could I make?
- Swap the positions of the 4 chess knights
- Rudimentary black jack game implementation
- 1 External SSD with OS and all files, used by 2 Macs, possible?
- Since what year would small-scale cheating have given an advantage in e.g. the World Championship?
- Were ancient Greece tridents different designs from other historical examples?
- Does "here" refer to a physical location or a metaphorical or emotional state?
- Which Old World ROM machines could officially run OS X?
- How widely is "where failure could result in death, injury, or damage" interpreted?
- Is there an equivalent of caniuse for commands on posix systems?
- Chemical Coin Flipping as Divination
- Postman signs for delivery himself. Any laws broken?
- What's that little animation between Avatar: The Last Airbender Book 2 and Book 3?
- Travel in Schengen with French residence permit stolen abroad
- Did a combined RAM+ROM chip ever exist?
- Can you shed some light on this dust-shielding ferrule?
- How would I translate GPT to German?
- How do I know if a motion is 1 dimensional or 2 dimensional?
- Why are some elves royalty?
- How can I connect my thick wires into an ikea wire connector
- Relation between Unity of Apperception and judgements in Kant
- Unused Private Pension fund transfer to offspring
- How many blocks per second can be sustainably be created using a time warp attack?
- Is it necessary to declare sins publicly?
Navigation Menu
Search code, repositories, users, issues, pull requests..., provide feedback.
We read every piece of feedback, and take your input very seriously.
Saved searches
Use saved searches to filter your results more quickly.
To see all available qualifiers, see our documentation .
- Notifications You must be signed in to change notification settings
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement . We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
local variable 'region_labels' referenced before assignment #2181
IEbokai commented May 14, 2024
I get this error when I run training: ############################ Using device: cuda:0 ####################################################################### 2024-05-14 20:41:51.961834: do_dummy_2d_data_aug: False |
The text was updated successfully, but these errors were encountered: |
The wrong fuction code is : ConvertSegmentationToRegionsTransform(SegOnlyTransform): def __init__(self, regions: Union[List, Tuple], channel_in_seg: int = 0): super().__init__() self.regions = regions self.channel_in_seg = channel_in_seg def _apply_to_segmentation(self, segmentation: torch.Tensor, **params) -> torch.Tensor: num_regions = len(self.regions) region_output = torch.zeros((num_regions, *segmentation.shape[1:]), dtype=torch.bool, device=segmentation.device) if isinstance(region_labels, int) or len(region_labels) == 1: if not isinstance(region_labels, int): region_labels = region_labels[0] region_output[:, region_id] = seg[:, self.seg_channel] == region_labels else: region_output[:, region_id] |= np.isin(seg[:, self.seg_channel], region_labels) return region_output.to(segmentation.dtype) |
Sorry, something went wrong.
jiashizuo commented May 26, 2024
Excuse me, have you solved it? I also encountered this error report. |
htcwf89 commented May 27, 2024
I'm running into the same error when trying to run region-based training. I traced the issue back to the "ConvertSegmentationToRegionsTransform" class in the batchgeneratorsv2 package (batchgeneratorsv2/batchgeneratorsv2/transforms/utils/seg_to_regions.py). p.s. I'm using nnunetv2 V2.5, torch 2.1.2+cu118, and batchgeneratorsv2 0.1.1 |
FabianIsensee commented May 28, 2024 • edited Loading
Hey, yeah that was dumbdumb. Fixed it now - please install nnUNetv2 and batchgeneratorsv2 from their respective master branches |
No branches or pull requests
UndboundLocalError: local variable referenced before assignment
Hello all, I’m using PsychoPy 2023.2.3 Win 10 x64bits
![unboundlocalerror local variable 'db' referenced before assignment image](https://global.discourse-cdn.com/business7/uploads/psychopy/original/3X/0/1/0151248d436b66d1e32c264550a4c46ec49ddc35.png)
What I’m trying to do? The experiment will show in the middle of the screen an abstracted stimuli (B1 or B2), and after valid click on it, the stimulus will remain on the middle of the screen and three more stimuli will appear in the cornor of the screen.
I’m having this erro (attached above), a simple error, but I can not see where the error is. Also the experiment isn’t working proberly and is the old version (I don’t know but someone are having troubles with this version of PscyhoPy)? ba_training_block.xlsx (13.8 KB) SMTS.psyexp (91.6 KB) stimuli, instructions and parameters.xlsx (12.8 KB)
You have a routine called sample but you also use that name for your image file in sample_box .
I changed the name of the routine for ‘stimulus_sample’ and manteined the image file in sample_box as ‘sample’. But, the error still remain. But it do not happen all the time, this is very interesting…
Can u give it a look again? (I made some minor changes here)
![unboundlocalerror local variable 'db' referenced before assignment image](https://global.discourse-cdn.com/business7/uploads/psychopy/original/3X/d/3/d392f5974b0c159115d0a91155ef5b845945e2f3.png)
Here the exp file ba_training_block.xlsx (13.7 KB) SMTS.psyexp (89.7 KB) stimuli, instructions and parameters.xlsx (12.8 KB)
Thanks again
Please could you confirm/show the new error message? Is it definitely still related to sample?
![unboundlocalerror local variable 'db' referenced before assignment image](https://global.discourse-cdn.com/business7/uploads/psychopy/optimized/3X/7/5/75f4b1745de0a83978131450c9e2c37a0221d2b1_2_690x387.png)
I think you have blank rows in your spreadsheet. The loop claims that there are 19 conditions but I think you only want 12. Without a value for sample_category sample doesn’t get set. With random presentation this will happen at a random point.
Related Topics
Topic | Replies | Views | Activity | |
---|---|---|---|---|
Builder | 10 | 4207 | February 9, 2024 | |
Builder | 2 | 209 | April 22, 2024 | |
Builder | 1 | 188 | October 17, 2023 | |
Builder | 2 | 524 | February 1, 2023 | |
Builder | 2 | 71 | June 29, 2024 |
- Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers
- Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand
- OverflowAI GenAI features for Teams
- OverflowAPI Train & fine-tune LLMs
- Labs The future of collective knowledge sharing
- About the company Visit the blog
Collectives™ on Stack Overflow
Find centralized, trusted content and collaborate around the technologies you use most.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
Get early access and see previews of new features.
UnboundLocalError: local variable 'data' referenced before assignment
I got a local error at first, and when I applied global to my code, I got a syntax error.
First, I got an error of UnboundLocalError: local variable 'data' referenced before assignment , then I added global data above the 2nd try . And now I got SyntaxError: name 'data' is assigned to before global declaration
I tried to solve it by applying other people's solutions but with no luck. How would you fix it? Thanks.
Update: data may have issue getting the value. When there's no value, an error will occur on the writerow line. But if I added except: None after the first try for the intention of returning None instead, as shown below:
It will generate a local variable error: local variable 'data' referenced before assignment . And the only way I have to do is to define data as global . I'm confused if I'm even on the right path. Or should there be any way to do rather than using except: None ? Thanks.
- Did you declare data before the function definition anywhere? By the way the error UnboundLocalError: local variable 'data' referenced before assignment shouldn't have come up with the code you have. Can you tell which line was the error pointing to? better yet, can you post the entire error stack trace? – SiddharthaRT Commented Mar 21, 2018 at 23:51
- @SiddharthaRT It points to the data variable in {'Column':data}. I was playing around and the error stack doesn't show up anymore. But it just hits except directly – Karma Commented Mar 21, 2018 at 23:59
- @SiddharthaRT I declared it inside the 1st try , nowhere else – Karma Commented Mar 22, 2018 at 0:03
The 'UnboundLocalError: local variable 'data' referenced before assignment' error indicates that 'data' has not been assigned when it is being called in Line 9 of your code. Either 'data' is defined outside of the get_data() function, or the initial try-block in which 'data' is defined is not being called.
I was able to get this code to run as expected -- double-check that your code is indented correctly and that there are no other formatting errors.
The following code functions as expected:
- It works fine except when data couldn't fetch any data, and it hits the first except: pass because it cannot write row. – Karma Commented Mar 22, 2018 at 0:38
Your Answer
Reminder: Answers generated by artificial intelligence tools are not allowed on Stack Overflow. Learn more
Sign up or log in
Post as a guest.
Required, but never shown
By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy .
Not the answer you're looking for? Browse other questions tagged python global local or ask your own question .
- The Overflow Blog
- How to bridge the gap between Web2 skills and Web3 workflows
- Featured on Meta
- Upcoming initiatives on Stack Overflow and across the Stack Exchange network...
- Announcing a change to the data-dump process
- What makes a homepage useful for logged-in users
Hot Network Questions
- Is 就 acceptable (even best) for "and so"?
- Can a group have a subgroup whose complement is closed under the group operation?
- "Four or six times", where is five?
- What hidden class abilities are there in D&D 5e?
- Rudimentary black jack game implementation
- Setting position of PlotLegends affect position of PlotLabel
- Swap the positions of the 4 chess knights
- In exercise 8.23 of Nielsen and Chuang why is the quantum operation no longer trace-preserving?
- Why is the MOSFET in this fan control circuit overheating?
- Do we always use "worsen" with something which is already bad?
- Why redirect_uri is needed when client_id is supplied in OAuth2?
- Are foldable tires less puncture resistant
- Is there a wavelength shift between sunlight observed from the ISS versus from Earth's surface?
- What is the function of this resistor and capacitor at the input of optoisolator?
- Is it rude to ask Phd student to give daily report?
- Is deciding to use google fonts the sort of decision that makes an entity a controller rather than a processor?
- Galilean invariance of the wave equation
- How to translate 戳着不动
- How well do universal rack rails work with vertical spacing?
- Do tech companies like Microsoft & CrowdStrike face almost no legal liabilities for major disruptions?
- Generalizations of Hamburger's Theorem
- Actix Web middleware to limit endpoint requests
- Unused Private Pension fund transfer to offspring
- How to access specific entry from list of arguments, when index is provided as a letter?
![](http://farmaciacoslada.online/777/templates/cheerup1/res/banner1.gif)
IMAGES
VIDEO
COMMENTS
File "weird.py", line 5, in main. print f(3) UnboundLocalError: local variable 'f' referenced before assignment. Python sees the f is used as a local variable in [f for f in [1, 2, 3]], and decides that it is also a local variable in f(3). You could add a global f statement: def f(x): return x. def main():
Output. Hangup (SIGHUP) Traceback (most recent call last): File "Solution.py", line 7, in <module> example_function() File "Solution.py", line 4, in example_function x += 1 # Trying to modify global variable 'x' without declaring it as global UnboundLocalError: local variable 'x' referenced before assignment Solution for Local variable Referenced Before Assignment in Python
If a variable is assigned a value in a function's body, it is a local variable unless explicitly declared as global. # Local variables shadow global ones with the same name You could reference the global name variable from inside the function but if you assign a value to the variable in the function's body, the local variable shadows the global one.
The UnboundLocalError: local variable 'x' referenced before assignment occurs when you reference a variable inside a function before declaring that variable. To resolve this error, you need to use a different variable name when referencing the existing variable, or you can also specify a parameter for the function. I hope this tutorial is useful.
Create Functions that Take in Parameters. UnboundLocalError: local variable 'DISTRO_NAME'. Solution 1. Solution 2. DJANGO - Local Variable Referenced Before Assignment [Form] Explanation. Local variable Referenced before assignment but it is global. Local variable 'version' referenced before assignment ubuntu-drivers. FAQs.
UnboundLocalError: local variable referenced before assignment. Example #1: Accessing a Local Variable. Solution #1: Passing Parameters to the Function. Solution #2: Use Global Keyword. Example #2: Function with if-elif statements. Solution #1: Include else statement. Solution #2: Use global keyword. Summary.
Avoid Reassignment of Global Variables. Below, code calculates a new value (local_var) based on the global variable and then prints both the local and global variables separately.It demonstrates that the global variable is accessed directly without being reassigned within the function.
Trying to assign a value to a variable that does not have local scope can result in this error: UnboundLocalError: local variable referenced before assignment. Python has a simple rule to determine the scope of a variable. If a variable is assigned in a function, that variable is local. This is because it is assumed that when you define a ...
I think you are using 'global' incorrectly. See Python reference.You should declare variable without global and then inside the function when you want to access global variable you declare it global yourvar. #!/usr/bin/python total def checkTotal(): global total total = 0
value = value + 1 print (value) increment() If you run this code, you'll get. BASH. UnboundLocalError: local variable 'value' referenced before assignment. The issue is that in this line: PYTHON. value = value + 1. We are defining a local variable called value and then trying to use it before it has been assigned a value, instead of using the ...
To fix this, you can either move the assignment of the variable x before the print statement, or give it an initial value before the print statement. def example (): x = 5 print (x) example()
PGRouting Layer plugin "UnboundLocalError: local variable 'db' referenced before assignment" Ask Question Asked 10 years, ... line 407, in run if db and db.con: UnboundLocalError: local variable 'db' referenced before assignment Python version: 2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)] QGIS version: 2.2.0-Valmiera ...
Before conducting it, I evaluated the buso of the ref genome protein is about 96%. Then I used the Liftoff to convert the gene and some other features to the new assemblied genome. I found that most of the genes can be converted, and then I used the gffread to extract the protein sequence based on the new converted gff3, while the buso is about ...
In order for you to modify test1 while inside a function you will need to do define test1 as a global variable, for example: test1 = 0. def test_func(): global test1. test1 += 1. test_func() However, if you only need to read the global variable you can print it without using the keyword global, like so: test1 = 0.
Additionally, it would be helpful to have the db written e.g. to the intermediate_files/ directory, which is guaranteed to have write access (or it should fail vocally before this step). Or some other way of controlling where it goes.
@Kohei-Fujiwara89 The permissions may indeed be an issue. Recall that you are trying to write to that file, so changing it so users can write might fix it. Alternately, you could just move your GFF to a different directory with write permissions and it might work.
I can see that, but that variable can not be referenced before being set to some value ie. a dictionary or another object. Somewhere there needs to exist something like this rootent = to_something then you can use, well only if that object has function called get()
local variable 'region_labels' referenced before assignment #2181. Closed IEbokai opened this issue May 14, 2024 · 4 comments Closed ... UnboundLocalError: local variable 'region_labels' referenced before assignment Traceback (most recent call last):
UndboundLocalError: local variable referenced before assignment. Coding. MarcelloSilvestre February 29, 2024, 12:17pm 1. Hello all, I'm using PsychoPy 2023.2.3 Win 10 x64bits. I am having a few issues in my experiment, some of the errors I never saw in older versions of Psychopy ... UnboundLocalError: local variable 'trialList' referenced ...
It will generate a local variable error: local variable 'data' referenced before assignment. And the only way I have to do is to define data as global. I'm confused if I'm even on the right path. Or should there be any way to do rather than using except: None? Thanks.