Question

USING RECURSION ONLY...NO ITERATION

Write a module called advancedmatch.py recursive function called ‘match(pattern, word)’ that can

be used to determine if a given pattern matches a given word.

In this case, a pattern consists of letters and ‘?’ and ‘*’ wildcards.

A ‘?’ wildcard matches any letter at the corresponding position in the word.

A ‘*’ wildcard matches zero or more letters at the corresponding position in the word.

Use aprogram called testadvanced.py that can be used to check your function.

Sample I/O:

Enter a pattern (or 'q' to quit):

l*ad

Enter a word:

launchpad

It's a match.

Enter a pattern (or 'q' to quit):

*ad

Enter a word:

lead It's a match.

Enter a pattern (or 'q' to quit):

**ad

Enter a word:

lard

They don't match.

Enter a pattern (or 'q' to quit):

q

HINTS:

? We now have an extra base case: if word is ‘’ and pattern is ‘*’ then return True.

? Generally, when the first character of the pattern is a ‘*’ wildcard, try to (i) match the rest of the pattern to the word, or (ii) match the pattern to the rest of the word.

Advancedmath:

import advancedmatch

def main():
pattern = input("Enter a pattern (or 'q' to quit):\n")
  
while (pattern!='q'):
word = input("Enter a word:\n")
if (advancedmatch.match(pattern, word)):
print("It's a match.")
else:
print("They don't match.")
pattern = input("Enter a pattern (or 'q' to quit):\n")
  
  
if __name__ == '__main__':
main()

Answer 1

def match(first, second):

if len(first) == 0 and len(second) == 0:

return True

if len(first) > 1 and first[0] == '*' and len(second) == 0:

return False

if (len(first) > 1 and first[0] == '?') or (len(first) != 0

and len(second) !=0 and first[0] == second[0]):

return match(first[1:],second[1:]);

if len(first) !=0 and first[0] == '*':

return match(first[1:],second) or match(first,second[1:])

return False

def test(first, second):

if match(first, second):

print("It's a match.")

else:

print("They don't match.")

pattern = input("Enter a pattern (or 'q' to quit):\n")

while (pattern!='q'):

word = input("Enter a word:\n")

test(pattern, word)

pattern = input("Enter a pattern (or 'q' to quit):\n")