In Python, is there a mean to enforce the use of spaces or tabs indentation with a per file basis ?
Well, perhaps \"enforce\" is too strong, more like a \"recommend
This is something your editor should do for you. Most editors (try Notepad++ for example, it's free) will let you set whether hitting tab enters a tab character or a number of spaces. I'd recommend using two spaces instead of tab in all files (I find 4 is too much). Using spaces instead of tabs is better as it means that you can indent stuff using both the space & tab keys without worrying about messing up your files.
If you have files that have a mix it isn't hard to write your own script to convert tabs to spaces
Tim Peters has written a nifty script called reindent.py which converts .py files to use 4-space indents and no tabs. It is available here, but check your distribution first -- it may have come bundled in an Examples or Tools directory. (On the latest LTS Ubuntu, it is provided by the python2.7-examples
package.)
If you can set up a Mercurial hook you should be able to run all files through reindent.py.
By the way, if you are using unix, then your system may also have the expand
(and unexpand
) command, which convert all tabs to spaces (and spaces to tabs). However, in this case, I think reindent.py
is the right tool.
As explicited in PEP 8, never mix tabs and space. However, a file with both may just run... As it says there:
The most popular way of indenting Python is with spaces only. The second-most popular way is with tabs only. Code indented with a mixture of tabs and spaces should be converted to using spaces exclusively. When invoking the Python 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!
the solution is therefore to use as a default:
python -t my_mixed_code.py
To answer at the editor level, this depends on the editor, please specify!
Look at the tabnanny module: — Detection of ambiguous indentation.