Question

Modify the find() function to locate a string within another string def find (astring, achar): Find and return the index of achar in astring Return 1 if achar does not occur in astring foundFalse while ix < len(astring) and not fo und: if astring[ix] achar found -True else: 1X - 1x +1 if found: return ix else: return1 For instance, print(find("abracadabra", "ra")) should return 2. It should function equivalently to the str.find) method but cannot use any existing method from the string class.

Answer 1

def find(astring, achar):
    # ix represents index of astring
    ix = 0
    # iy represents index of achar
    iy = 0

    # Iterate loop till ix+iy is < less than length of astring
    while ix + iy < len(astring):
        # If character does not match, increment ix by 1
        # Re-set iy to 0
        if astring[ix + iy] != achar[iy]:
            ix += 1
            iy = 0
            continue

        # Otherwise, increment iy by 1 to check for next character in achar
        iy += 1

        # If iy equals length of achar means all character matched, return ix
        if iy == len(achar):
            return ix
    # Return -1
    return -1


print(find("abracadabra", "ra"))
print(find("abracadabra", "a"))
print(find("abracadabra", "ara"))
print(find("Hello", "lo"))

SCREENSHOT

FHindstring.py def find (astring, achar): # ix represents index of astring 1x = 0 # y represents index of achar ly = 0 2 3 # Iterate loop till 1xty is < less than length of astring while ix + iy < len (astring): # If character does not match, increment ix by 1 # Re-set ly to 0 if astring[ix + iy] != achar [ly] : 10 12 13 14 15 16 17 18 19 20 21 1x += 1 ly = 0 continue # Otherwise, increment y by 1 to check for next character in achar iy +1 # If y equals length of achar means all character matched, return ix if iy len (achar): return ix # Return -1 23 24 25 26 27 28 29 return -1 print (find ("abracadabra", "ra" print (find ( "abracadabra", "a")) print (find ("abracadabra", "ara")) print (find ("Hello", "lo")

OUTPUT

FindString E: \Practice\Pyth 2 3 Process finished