Check if an IP address is entered correctly [no expression, only if, else, for ecc.]

ipAddressForLoops.py

# ipAddress = input("please enter an ipAddress: ")
ipAddress = "192.168.7.7"


# check if number of dots is 3
numberOfDot = 0
for char in ipAddress:
    if char == '.':
        numberOfDot += 1
totNumbOfDot = numberOfDot  # output of this section is totNumberOfDot, to be checked at the end
if totNumbOfDot != 3:
    print("You inserted a wrong ip address")

# maybe here should be inserted an else to constrain all the following
# because if dots are != from 3 everything is wrong

# first number check
number1 = ''
for char in ipAddress:
    if char in "0123456789":
        number1 += char
    if char == '.':
        break
if 1 <= len(number1) <= 3:
    print("First number:   OK")
else:
    print("First number:   Fail")
digitN1 = len(number1) + 1
print(number1)


# second number check
numberMinus2 = ipAddress[digitN1:]
number2 = ''
for char in numberMinus2:
    if char in "0123456789":
        number2 += char
    if char == '.':
        break
if 1 <= len(number2) <= 3:
    print("Second number:  OK")
else:
    print("Second number: Fail")
digitN2 = len(number2) + digitN1 +1
print(number2)


# third number check
numberMinus3 = ipAddress[digitN2:]
number3 = ''
for char in numberMinus3:
    if char in "0123456789":
        number3 += char
    if char == '.':
        break
if 1 <= len(number3) <= 3:
    print("Third number:   OK")
else:
    print("Third number:   Fail")
digitN3 = len(number3) + digitN2 + 1
print(number3)


# fourth number check
numberMinus4 = ipAddress[digitN3:]
number4 = ''
for char in numberMinus4:
    if char in "0123456789":
        number4 += char
    if char == '.':
        break
if 0 < len(number4) <= 3:
    print("Fourth number:  OK")
else:
    print("Fourth number:  Fail")
digitN4 = len(number4) + digitN3 + 1
print(number4)