Python: Using a regex to change a path allowing for windows and linux

veryangryman

So we have a path where we want to change directory relative to where we are.

The absolute_path variable will have windows or linux style based on the OS used so we had to rejig the code, swapping \ for / to allow for this at the replace part if windows is detected.

        absolute_path = path.dirname(path.abspath(__file__))
        this_is_windows = False
        if '\\' in absolute_path:
            this_is_windows = True # Windows path
            key_path_before = absolute_path.replace('\\', '/')
        else:
            key_path_before = absolute_path

        key_path = key_path_before.replace("lib/proj/projx/utils/CE/ce_common_utils",
                                                                    "tests/projx/CE/oci_keys")

Id rather do this in a regex but suck at them

So i want to replace..

Everything starting with "lib" and ending with "ce_common_utils" (storing the seperator)

with

tests/projx/CE/oci_keys (using the seperator where those "/" are)

Talisman

You're over thinking the problem, there's no need for regex just use the standard library functions for your purpose.

file_path = "lib/proj/projx/CE/ce_common_utils"

file_path = os.path.relpath(file_path, "")

On Windows this will transform the string to "lib\\proj\\projx\\CE\\ce_common_utils".

A function to do the folder path change.

def change_folder_path(full_path, orig_sub, new_sub):
     full_path = os.path.relpath(full_path, "")
     orig_sub = os.path.relpath(orig_sub, "")
     new_sub = os.path.relpath(new_sub, "")
     return full_path.replace(orig_sub, new_sub)

So in your code you call:

key_path = change_folder_path(key_path_before,
                              "lib/proj/projx/utils/CE/ce_common_utils",
                              "tests/projx/CE/oci_keys")

Google regex tester or regex generator to help you figure what the regex for your string should be

Jadgpanzer

On a side note, whenever you have path parts as strings with no delimiters then you can use:

os.path.join(part1, part2, part3)

which will automatically join strings using the correct delimiters. As veryangryman said, standard library functions are the way to go