CODEWITHSUNDEEP
python
Shay Erlichmen
Shay Erlichmen

Reputation: 31928

How to fix Python indentation

I have some Python code that have inconsistent indentation. There is a lot of mixture of tabs and spaces to make the matter even worse, and even space indentation is not preserved.

The code works as expected, but it's difficult to maintain.

How can I fix the indentation (like HTML Tidy, but for Python) without breaking the code?

Some editor-specific advice:

Upvotes: 304

Views: 383550

Answers (14)

Pedro Lobito
Pedro Lobito

Reputation: 99011

autopep8 -i script.py

You can use autopep8

autopep8 automagically formats Python code to conform to the PEP 8 nullstyle guide. It uses the pep8 utility to determine what parts of the nullcode needs to be formatted. autopep8 is capable of fixing most of the nullformatting issues that can be reported by pep8.

pip install autopep8
autopep8 script.py    # print only
autopep8 -i script.py # write file

Upvotes: 63

Kamil Kuczaj
Kamil Kuczaj

Reputation: 303

There is also a Google awesome project called YAPF

It can automatically reformat the whole project or check if the project has correct indentation/format. I used that in a commercial project and I recommend that.

Upvotes: 0

Alex Martelli
Alex Martelli

Reputation: 882621

Use the reindent.py script that you find in the Tools/scripts/ directory of your Python installation:

Change Python (.py) files to use 4-space indents and no hard tab characters. Also trim excess spaces and tabs from ends of lines, and remove empty lines at the end of files. Also ensure the last line ends with a newline.

Have a look at that script for detailed usage instructions.

NOTE: If your linux distro does not have reindent installed by default with Python:

Many linux distros do not have reindent installed by default with python --> one easy way to get reindent is to do pip install reindent.

p.s. An alternative to pip is to use your distros package manager (i.e. apt-get, yum, dnf) but then you need to figure out what package has the command line tool because each distro has the tool in a different package.

Upvotes: 302

Mehrdad Salimi
Mehrdad Salimi

Reputation: 1426

In case of trying to find tool to make your 2-space indented python script to a tab indented version, just use this online tool:

https://www.tutorialspoint.com/online_python_formatter.htm

Upvotes: 0

Martin Vegter
Martin Vegter

Reputation: 527

The reindent script did not work for me, due to some missing module. Anyway, I found this sed command which does the job perfect for me:

sed -r 's/^([  ]*)([^ ])/\1\1\2/' file.py

Upvotes: 6

anshuman
anshuman

Reputation: 3544

Try IDLE, and use Alt + X to find indentation.

Upvotes: 2

Paul Hildebrandt
Paul Hildebrandt

Reputation: 2754

There is also PythonTidy (since you said you like HTML Tidy).

It can do a lot more than just clean up tabs though. If you like that type of thing, it's worth a look.

Upvotes: 11

Arnkrishn
Arnkrishn

Reputation: 30442

Try Emacs. It has good support for indentation needed in Python. Please check this link http://python.about.com/b/2007/09/24/emacs-tips-for-python-programmers.htm

Upvotes: 3

Ben Hughes
Ben Hughes

Reputation: 14195

Using Vim, it shouldn't be more involved than hitting Esc, and then typing...

:%s/\t/    /g

...on the file you want to change. That will convert all tabs to four spaces. If you have inconsistent spacing as well, then that will be more difficult.

Upvotes: 18

Andy Hayden
Andy Hayden

Reputation: 375855

I would reach for autopep8 to do this:

$ # see what changes it would make
$ autopep8 path/to/file.py --select=E101,E121 --diff

$ # make these changes
$ autopep8 path/to/file.py --select=E101,E121 --in-place

Note: E101 and E121 are pep8 indentation (I think you can simply pass --select=E1 to fix all indentation related issues - those starting with E1).

You can apply this to your entire project using recursive flag:

$ autopep8 package_dir --recursive --select=E101,E121 --in-place

See also Tool to convert Python code to be PEP8 compliant.

Upvotes: 69

Crowman
Crowman

Reputation: 25936

On most UNIX-like systems, you can also run:

expand -t4 oldfilename.py > newfilename.py

from the command line, changing the number if you want to replace tabs with a number of spaces other than 4. You can easily write a shell script to do this with a bunch of files at once, retaining the original file names.

Upvotes: 8

hanqiang
hanqiang

Reputation: 567

I have a simple solution for this problem. You can first type ":retab" and then ":retab!", then everything would be fine

Upvotes: 0

Yansky
Yansky

Reputation: 4760

If you're lazy (like me), you can also download a trial version of Wingware Python IDE, which has an auto-fix tool for messed up indentation. It works pretty well. http://www.wingware.com/

Upvotes: 5

ephemient
ephemient

Reputation: 204974

If you're using Vim, see :h retab.

                                                        *:ret* *:retab*
:[range]ret[ab][!] [new_tabstop]
                        Replace all sequences of white-space containing a
                        <Tab> with new strings of white-space using the new
                        tabstop value given.  If you do not specify a new
                        tabstop size or it is zero, Vim uses the current value
                        of 'tabstop'.
                        The current value of 'tabstop' is always used to
                        compute the width of existing tabs.
                        With !, Vim also replaces strings of only normal
                        spaces with tabs where appropriate.
                        With 'expandtab' on, Vim replaces all tabs with the
                        appropriate number of spaces.
                        This command sets 'tabstop' to the new value given,
                        and if performed on the whole file, which is default,
                        should not make any visible change.
                        Careful: This command modifies any <Tab> characters
                        inside of strings in a C program.  Use "\t" to avoid
                        this (that's a good habit anyway).
                        ":retab!" may also change a sequence of spaces by
                        <Tab> characters, which can mess up a printf().
                        {not in Vi}
                        Not available when |+ex_extra| feature was disabled at
                        compile time.

For example, if you simply type

:ret

all your tabs will be expanded into spaces.

You may want to

:se et  " shorthand for :set expandtab

to make sure that any new lines will not use literal tabs.

If you're not using Vim,

perl -i.bak -pe "s/\t/' 'x(8-pos()%8)/eg" file.py

will replace tabs with spaces, assuming tab stops every 8 characters, in file.py (with the original going to file.py.bak, just in case). Replace the 8s with 4s if your tab stops are every 4 spaces instead.

Upvotes: 62

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