TabError inconsistent use of tabs and spaces in indentation

In Python, You can indent using tabs and spaces in Python. Both of these are considered to be whitespaces when you code. So, the whitespace or the indentation of the very first line of the program must be maintained all throughout the code. This can be 4 spaces, 1 tab or space. But you must use either a tab or a space to indent your code.

But if you mix the spaces and tabs in a program, Python gets confused. It then throws an error called “TabError inconsistent use of tabs and spaces in indentation”.

In this article, we delve into the details of this error and also look at its solution.

How to fix 'TabError: inconsistent use of tabs and spaces in indentation'?

Example:

a = int(input("Please enter an integer A: ")) b = int(input("Please enter an integer B: ")) if b > a:

   print("B is greater than A")  

   print("A and B are equal")  

   print("A is greater than B")  

Output:

TabError: inconsistent use of tabs and spaces in indentation

When the code is executed, the “TabError inconsistent use of tabs and spaces in indentation”. This occurs when the code has all the tabs and spaces mixed up.

To fix this, you have to ensure that the code has even indentation. Another way to fix this error is by selecting the entire code by pressing Ctrl + A. Then in the IDLE, go to the Format settings. Click on Untabify region.

Solution:

1. Add given below line at the beginning of code

#!/usr/bin/python -tt

2. Python IDLE

In case if you are using python IDLE, select all the code by pressing (Ctrl + A) and then go to Format >> Untabify Region

So, always check the placing of tabs and spaces in your code properly. If you are using a text editor such as Sublime Text, use the option Convert indentation to spaces to make your code free from the “TabError: inconsistent use of tabs and spaces in indentation” error.

The Python "TabError: inconsistent use of tabs and spaces in indentation" occurs when we mix tabs and spaces in the same code block.

To solve the error, remove the spacing and only use tabs or spaces, but don't mix the two in the same code block.

Here is an example of how the error occurs.

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# ⛔️ TabError: inconsistent use of tabs and spaces in indentation if len('hi') == 2:

print('a')
print('b')

The first line in the code block was indented using tabs, and the second using spaces and tabs.

The screenshot shows that the print('a') line was indented using tabs (arrows), and the print('b') line was indented using spaces and tabs (dots and arrows).

Only indent the lines using tabs or spaces

To solve the error, remove the whitespace and only indent the lines in the code block using tabs or using spaces.

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

Make sure the lines of code in the code block at indented to the same level.

You can either indent your code using tabs or using spaces.

However, you shouldn't mix tabs and spaces in the same code block as that often causes issues in Python.

Your error message should show the exact location where the error is raised, so you can remove the whitespace and consistently indent the lines in the code block using tabs or spaces.

Convert indentation to spaces or tabs

If you use VSCode, you can solve the error by using the "Convert indentation to spaces" or "Convert indentation to tabs" commands:

1. press CTRL + Shift + P or (⌘ +

   Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   0 + Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   1 on Mac) to open the command palette.
2. type: "convert indentation to"
3. Select your preferred option
4. Save the file

Showing the whitespace characters in your IDE

If you use VSCode, you can show whitespace characters by:

1. pressing CTRL + Shift + P or (⌘ +

   Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   0 + Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   1 on Mac) to open the command palette.
2. typing "open workspace settings"
3. typing

   Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   6
4. setting it to

   Copied!

   ✅ correctly indented code

   if len('hi') == 2:

   print('a')  
   print('b')  
   

   7

If you render whitespace characters in your IDE, tabs should show as arrows and spaces should show as dots.

If you use Sublime Text, you can set it to use Tabs for indentation by:

• Clicking on View -> Indentation -> Convert indentation to Tabs

You can also uncheck the Indent using spaces checkbox if you have it checked.

It is a matter of personal preference if you use only tabs or only spaces, but make sure not to mix the two.

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# ✅ consistently indented code def my_function():

if len('hi') == 2:
    print('a')
    print('b')
elif len('one' == 1):
    print('c')
else:
    print('d')

Note that if you use tabs in one code block and spaces in the other, you won't get an error.

The error is only raised if you mix tabs and spaces in the same code block.

The upper

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

8 statement uses tabs for indentation and the lower uses spaces.

The example doesn't cause an error because we didn't mix tabs and spaces in the same code block.

Using the

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

9 module to solve the error

The autopep8 module automatically formats code to the PEP 8 style guide.

The module can be used to fix indentation errors.

You can install

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

9 by running the following command.

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`pip install --upgrade autopep8

👇️ or with pip3

pip3 install --upgrade autopep8

👇️ in case you don't have PIP in PATH environment variable

python -m pip install --upgrade autopep8 python3 -m pip install --upgrade autopep8

👇️ for Windows

py -m pip install --upgrade autopep8 `

Now you can use the

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

9 command to solve the error.

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autopep8 -i main.py

Make sure to save your file after running the

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# ✅ correctly indented code if len('hi') == 2:

print('a')
print('b')

9 command.

Using tabnanny to detect indentation errors

You can use the

Copied!

# ✅ consistently indented code def my_function():

if len('hi') == 2:
    print('a')
    print('b')
elif len('one' == 1):
    print('c')
else:
    print('d')

3 built-in module to detect on which line the indentation error occurred.

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`python -m tabnanny main.py

👇️ for Python 3

python3 -m tabnanny main.py

👇️ for Windows

py -m tabnanny main.py `

Make sure to replace

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# ✅ consistently indented code def my_function():

if len('hi') == 2:
    print('a')
    print('b')
elif len('one' == 1):
    print('c')
else:
    print('d')

4 with the name of the file that contains the error.

The error message shows that the error occurred on line 3.

In other words, I have to remove the leading whitespace from line 3 and indent the code consistently (using only spaces or only tabs).

Solving the error in the IDLE code editor

If you got the error in the IDLE code editor:

1. Click on Edit in the top menu and then click Select all.
2. Click on Format in the top menu and then click Untabify Region.

After you click on the OK button, save your file and you should be good to go.

The pep8 style guide recommends using spaces

The recommends using spaces over tabs for indentation.

According to the recommendation, tabs should be used in a code base that is already indented using tabs.

However, they recommend using spaces for new projects.

As previously noted, Python disallows mixing tabs and spaces for indentation.

Whether you use tabs or spaces is a matter of personal preference, but make sure to not mix the two in the same codebase as that often causes issues in Python.