Script to collect latest drawings from a Momentum project folder

collect_drwgs.py

#!/usr/bin/env python

'''
This script collects latest drawings from an Momentum project folder
and puts them into a `Current documents` folder. If that folder already
exists, its content is attemptingly moved to a `SS` subfolder.

This script should be located in the `Document issues` folder of a 
project.
'''

from collections import defaultdict
from pathlib import Path
from shutil import copy2, move, SameFileError


digit = '[0123456789]'
file_ext = 'pdf'

# Pattern is designed to look into dated folders (starting with 6 digits)
# and look for filenames that start with a project number (4 digits), contain
# the sequence '-MOM-' and end with the extension specified.

pattern = digit * 6 + '*/' + digit * 4 + '-MOM-*.' + file_ext

# Length of revision code
n_char = 3

# Admissible revision prefixes with their order as values
prefix = {
    'P': '0',
    'C': '1',
}

# Destination folder name
dest = 'Current documents'


def get_rev_code(path):
    '''
    Returns the segment of the filename after the last '-' in upper case.
    '''
    return path.stem.rsplit('-', maxsplit=1)[-1].upper()


def is_rev_code_valid(rev_code):
    '''
    Checks if a revision code is valid, i.e. it is the correct length and
    starts with one of the `prefix` keys followed by digits only.
    '''
    rev_code = str(rev_code)
    if (
            len(rev_code) == n_char 
            and rev_code.startswith(tuple(prefix.keys()))
            and rev_code[1:n_char].isdecimal()
        ):
        return True
    return False

        
def rev_code_rank(path):
    '''
    Returns a translating string reflecting the order of revisions based
    on the prefixes' order.
    The first letter gets substitued for a numerical character that reflects
    the prefix order. 
    '''
    rev_code = get_rev_code(path)
    return rev_code.translate(str.maketrans(prefix))


# Get path to current working directory, the 'Issues' folder of a project.
p = Path.cwd()

valid, invalid = defaultdict(list), []

# Create a destination and 'ss' folder if necessary.
dest_path = p / dest
ss_path = dest_path / 'ss'
ss_path.mkdir(parents=True, exist_ok=True)

# Move files present in the dest folder to 'ss' if possible.
for f in dest_path.glob('*.' + file_ext):
    try:
        move(f, ss_path)
    except:
        continue
 
# Group files matching pattern by their name and list all revisions, 
# list invalid files too.
for f in p.rglob(pattern):
    title = f.stem.split(maxsplit=1)[0][:-n_char]
    if title.endswith('-') and is_rev_code_valid(get_rev_code(f)):
        valid[title].append(f)
    else:
        invalid.append(f)

# With valid files, find the latest issue and copy it to the dest folder.
while valid:
    title, revs = valid.popitem()
    latest = max(revs, key=rev_code_rank)
    try:
        copy2(latest, dest_path / latest.name)
    except SameFileError:
        pass

# Print the list of invalid files.
print(*(f for f in invalid), sep='\n')