Python: Recursively modifying strings

Question

My goal is to recursively modify a string, such that if it is greater than 48 characters in length, the last word will be removed. If/once the string is not greater than 48 characters in length, return it.

This is my attempt:

def checkLength(str):
  if len(str) > 48:
    str = str.rsplit(' ',1)[0]
    checkLength(str)
  else:
    return str

Passing a string > 48 characters long results in an empty value.

What is the correct way to achieve this in Python, and why does the above function not work as one might expect?

Also, don't use `str` as a variable name, it shadows the built-in type. — Daniel Roseman, Nov 22 '16 at 18:28

score 2 · Accepted Answer · answered Nov 22 '16 at 18:28

2

def checkLength(my_str):
  if len(my_str) > 48:
    my_str = str.rsplit(' ',1)[0]
    # you must return the recursive call! 
    return checkLength(my_str)
  else:
    return my_str

answered Nov 22 '16 at 18:28

Joran Beasley

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Python: Recursively modifying strings

1 Answers1