pattern.py

pattern_lines = """
f 1 2 3
f 1/2 3/4 5/6
f 1//2 3//4 5//6
f 1/2/3 4/5/6 7/8/9
"""
for pattern in pattern_lines.splitlines():
  if pattern.beginsWith("f"):
    line_begins_with_f(pattern)

def line_begins_with_f(pattern):
  if pattern.matches("\/\/[\d\.]+\s"):
    do_something(pattern)
    continue
  if pattern.matches("\/[\d\.]+\/"):
    do_something_else(pattern)
    continue
  if pattern.matches("\/[\d\.]+"):
    do_something_different(pattern)
    continue
  do_something_something(pattern)