How to fix Python indentation

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

Change Python (.py) files to use4-space indents and no hard tabcharacters. Also trim excess spacesand tabs from ends of lines, andremove empty lines at the end offiles. Also ensure the last line endswith 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.

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.

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.