demo

~/test$ printf "    a\n      b\n     c\n"
    a
      b
     c
~/test$ printf "    a\n      b\n     c\n" | python3 -m textwrap-tool dedent
a
  b
 c

~/test$ printf "    a\n      b\n     c\n" | python3 -m textwrap-tool indent '....'
....    a
....      b
....     c

~/test$ printf "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" | python3 -m textwrap-tool wrap 10
1234567890
abcdefghij
klmnopqrst
uvwxyzABCD
EFGHIJKLMN
OPQRSTUVWX
YZ
~/test$ 

textwrap-tool.py

import sys
from textwrap import wrap, fill, shorten, dedent, indent

args = sys.argv[2:]

if len(args) > 0 and sys.argv[1] in ['wrap', 'fill', 'shorten']:
    args[0] = int(args[0])

fns = {'wrap': wrap, 'fill': fill, 'shorten': shorten, 'dedent': dedent, 'indent': indent}
ret = fns[sys.argv[1]](sys.stdin.read(), *args)

if isinstance(ret, list):
    # Handle things like wrap(), which returns a list.
    print('\n'.join(ret))
else:
    print(ret)