(python) recursively remove capitalisation from directory structure?

Question

uppercase letters - what's the point of them? all they give you is rsi.

i'd like to remove as much capitalisation as possible from my directory structure. how would i write a script to do this in python?

it should recursively parse a specified directory, identify the file/folder names with capital letters and rename them in lowercase.

Answer 1

try the following script:

#!/usr/bin/python

'''
renames files or folders, changing all uppercase characters to lowercase.
directories will be parsed recursively.

usage: ./changecase.py file|directory
'''

import sys, os

def rename_recursive(srcpath):
    srcpath = os.path.normpath(srcpath)
    if os.path.isdir(srcpath):
        # lower the case of this directory
        newpath = name_to_lowercase(srcpath)
        # recurse to the contents
        for entry in os.listdir(newpath): #FIXME newpath
            nextpath = os.path.join(newpath, entry)
            rename_recursive(nextpath)
    elif os.path.isfile(srcpath): # base case
        name_to_lowercase(srcpath)
    else: # error
        print "bad arg: " + srcpath
        sys.exit()

def name_to_lowercase(srcpath):
    srcdir, srcname = os.path.split(srcpath)
    newname = srcname.lower()
    if newname == srcname:
        return srcpath
    newpath = os.path.join(srcdir, newname)
    print "rename " + srcpath + " to " + newpath
    os.rename(srcpath, newpath)
    return newpath

arg = sys.argv[1]
arg = os.path.expanduser(arg)
rename_recursive(arg)

Answer 2

os.walk is great for doing recursive stuff with the filesystem.

import os

def lowercase_rename( dir ):
    # renames all subforders of dir, not including dir itself
    def rename_all( root, items):
        for name in items:
            try:
                os.rename( os.path.join(root, name), 
                                    os.path.join(root, name.lower()))
            except OSError:
                pass # can't rename it, so what

    # starts from the bottom so paths further up remain valid after renaming
    for root, dirs, files in os.walk( dir, topdown=False ):
        rename_all( root, dirs )
        rename_all( root, files)

The point of walking the tree upwards is that when you have a directory structure like '/A/B' you will have path '/A' during the recursion too. Now, if you start from the top, you'd rename /A to /a first, thus invalidating the /A/B path. On the other hand, when you start from the bottom and rename /A/B to /A/b first, it doesn't affect any other paths.

Actually you could use os.walk for top-down too, but that's (slightly) more complicated.