Why do I get a `TabError` from code that appears to be properly aligned?

Question

The following python code throws this error message, and I can't tell why, my tabs seem to be in line:

File "test.py", line 12
    pass
       ^
TabError: inconsistent use of tabs and spaces in indentation

class eightPuzzle(StateSpace):
    StateSpace.n = 0
    
    def __init__(self, action, gval, state, parent = None):
        StateSpace.__init__(self, action, gval, parent)
        self.state = state

    def successors(self) :
        pass

Did you use tabs for one line, and spaces for the other? You can configure you editor to always use 4 spaces when you tab to be consistent. — dannymilsom, Feb 04 '15 at 15:49
Please format your code with the class declaration in the code block. — Malik Brahimi, Feb 04 '15 at 15:52
I'm willing to bet, that you didn't indent your instance methods under the class declaration. — Malik Brahimi, Feb 04 '15 at 15:53
I tried to fix the post so that it would show the actual tab and space characters that OP had for indentation in the original code; but it appears that Stack Overflow's Markdown renderer will convert tabs to spaces anyway, rendering that impossible. — Karl Knechtel, Jan 22 '23 at 11:11

score 10 · Answer 1 · answered Feb 04 '15 at 16:09

You cannot mix tabs and spaces, according the PEP8 styleguide:

Spaces are the preferred indentation method.

Tabs should be used solely to remain consistent with code that is already indented with tabs.

Python 3 disallows mixing the use of tabs and spaces for indentation.

Python 2 code indented with a mixture of tabs and spaces should be converted to using spaces exclusively.

When invoking the Python 2 command line interpreter with the -t option, it issues warnings about code that illegally mixes tabs and spaces. When using -tt these warnings become errors. These options are highly recommended!

score -1 · Answer 2 · answered Mar 04 '20 at 08:46

-1

Using Visual Studio 2019

I was using tabs but the editor was inserting spaces and it would result in errors.

To avoid getting the spaces and tabs mixed up , set your preferences

Go to Edit->Advanced->Set Leading Whitespace->Tabs (or Whitespaces)

After I set it to Tabs, my tabs stop being represented as spaces and it worked fine thereafter

answered Mar 04 '20 at 08:46

Sujit Bhattacharyya

49
4

Nothing in the question mentions Visual Studio. You should create your own question (and possibly also answer it) when having a problem with a more specific environment. – sampi Jul 21 '22 at 06:01

score -1 · Answer 3 · answered Jan 22 '23 at 10:50

-1

For linux nano users:

if your code includes 4 spaces instead of a tab, you should keep using 4 spaces or change all of them to a tab. If you use mixed it gives an error.

answered Jan 22 '23 at 10:50

saitamatechno

49
6

score -2 · Answer 4 · answered Jun 29 '17 at 18:28

-2

open your code in a text editor, highlight all of it (ctr+a) and go to format and select either "Tabify region" or "Untabify region". It'll just make all the indents have the same format.

answered Jun 29 '17 at 18:28

skm

1

1

My text editor doesn't have a Format menu! And how do you know all editors' indentation commands will make tabs consistent? – Nathan Tuggy Jun 29 '17 at 18:57
I believe all code editors have some feature like this. It might be called "reindent", "auto indent" or somthing like that. – Håken Lid Jun 29 '17 at 19:06
I used the leafpad text editor and this is how I was able to fix the error. It will either make your indents be all tabs or all spaces – skm Jun 30 '17 at 13:03

score -2 · Answer 5 · edited Jul 25 '19 at 08:24

-2

not using the backspace also is important (especially in the Leafpad editor). If you want to decrease indent, use only Alt_key + TAB.

This should be done when you delete a line in a Python code.

edited Jul 25 '19 at 08:24

zaerymoghaddam

3,037
1
27
33

answered Jul 25 '19 at 07:41

Eranga De Silva

1

Why do I get a `TabError` from code that appears to be properly aligned?

5 Answers5

Linked

Related