isalpha() and isdigit()-Manually- NLP

isalpha() is function built-in method which check whether all character in the string is alphabet.

print("Heydude".isalpha())
print("H@y d1ude".isalpha())

Output:
True
False

Now we will do it manually, apply logic to make isalpha():

def isalpha(text):
    counter=0
    for i in text:
        if((ord(i)>=65 and ord(i)<=90) or (ord(i)>=97 and ord(i)<=122)):
            counter+=1
    if (len(text)==counter):
        return True
    else:
        return False
        
print(isalpha("Hey"))
print(isalpha("123"))

True
False

Explanation:

1. Take Counter to count character in string.
2. Iterate through text.
3. There conditions which check if alphabet lies in that ASCII range and it is for lower case and upper case.
4. If there no alphabet then loop break and come out.
5. Then check length of text and counter if it is same then return True or False

isdigit() is function built-in method which check whether all character in the string is digit.

print("Heydude".isdigit())
print("234567".isdigit())

Output:
False
True

Now we will do it manually, apply logic to make isdigit():

def isdigit(text):
    counter=0
    for i in text:
        if((ord(i)>=48 and ord(i)<=57)):
            counter+=1
    if (len(text)==counter):
        return True
    else:
        return False
        
print(isdigit("Hey"))
print(isdigit("123"))

False
True

Explanation:

1. Take Counter to count character in string.
2. Iterate through text.
3. There conditions which check if digit lies in that ASCII range.
4. If there no digit then loop break and come out.
5. Then check length of text and counter if it is same then return True or False