Python - find a substring in string and record position of substrings in a tuple

I am getting the below error when I check this function. I am very close, but not understanding why the loop continues after reaching the end of the text. How do I get it to stop searching for the substring after it has reached the end of the string to search?

Error: The call findall('how now brown cow', 'ow') returns (1, 5, 10, 15, -1, 1, 5, 10, 15, -1, 1, 5, 10, 15, -1, 1, 5), not (1, 5, 10, 15).

Note - I have searched through the similar problems here in stack overflow, but do not see anything that is helping me resolve this using the method I have prepared so far. Please advise. Greatly appreciated for this newbie!! :)

def findall(text,sub):      """      Returns the tuple of all positions of substring sub in text.            If sub does not appears anywhere in text, this function returns the       empty tuple ().            Examples:          findall('how now brown cow','ow') returns (1, 5, 10, 15)          findall('how now brown cow','cat') returns ()          findall('jeeepeeer','ee') returns (1,2,5,6)            Parameter text: The text to search      Precondition: text is a string            Parameter sub: The substring to search for      Precondition: sub is a nonempty string      """      result = ()      x = 0      pos = 0            for x in range(len(text)):          if sub in text:                  # find pos of sub in text starting from pos in text              pos = introcs.find_str(text,sub,pos)              # record result              result = result + (pos,)              # increase accumulator by 1 to find next pos of sub in text              pos = pos + 1          else:              # when sub is not present in text              result = ()             return result  

https://stackoverflow.com/questions/67237702/python-find-a-substring-in-string-and-record-position-of-substrings-in-a-tuple April 24, 2021 at 06:55AM