CS50P PSETS 2, Vanity plates

Marco Cracco 0
Viewed 49

I'm having some issues with the psets 2 of cs50p, precisely I'm talking about the "Vanity Plates" problem, where I fulfilled all requests except one, which said:

“Numbers cannot be used in the middle of a plate; they must come at the end. For example, AAA222 would be an acceptable … vanity plate; AAA22A would not be acceptable. The first number used cannot be a ‘0’.” Can you help me? Thank's

this is the code I wrote so far:

def main():
plate = input("Plate: ")
if is_valid(plate):
print("Valid")
else:
print("Invalid")

def is_valid(s):
if s.isalnum() | s[:2].isalpha() | 2 < len(s) < 6 | :
else:
return False

main()
cs50 python
1 Answers

you have to consider all the cases one by one, this is how I solved it:

def main():
    plate = input("Plate: ")
    if is_valid(plate):
        print("Valid")
    else:
        print("Invalid")


def is_valid(s):
    if  len(s) < 2 or len(s) > 6:
        return False
    elif not s[0].isalpha() or not s[1].isalpha():
        return False
    elif checkFirstZero(s):
        return False
    elif checkMiddleZero(s):
        return False
    elif last(s):
        return False
    elif worng(s):
        return False
    return True

def last(s):
    isAlp = False
    isNum = False
    for w in s:
        if not w.isalpha():
            isNum = True
        else:
            if isNum:
                return True
    return False

def checkCuntuNNumber(s):
    isFirstTry = True
    isNum = False
    for w in s:
        if not w.isalpha():
            if isFirstTry:
                isNum = True
                isFirstTry = False
    if isNum and s[-1].isalpha():
        return True


def checkMiddleZero(s):
    isFirstTry = True
    isNum = False
    for w in s:
        if not w.isalpha():
            if isFirstTry:
                isNum = True
                isFirstTry = False
    if isNum and s[-1].isalpha():
        return True
    else:
        return False

def checkFirstZero(s):
    for w in s:
        if not w.isalpha():
            if int(w) == 0:
                return True
            else:
                return False

def worng(s):
    for w in s:
        if w in [" ", ".", ","]:
            return True
    return False


main()
Rohit Bhati0
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