1.pincode validation :
- Must be 6 digits
- Only numbers (no letters, no symbols)
- first digit can’t be 0
def pincode(pc):
if pc//100000!=0 and pc//100000<=9:
print("valid")
else:
print("invalid")
pincode(int(input("Enter your 6 digit pin code :")))
2.Gmail validation :
- Allow only characters: a–z, A–Z, 0–9, '@', '.', '_'.
- If any other character appears → invalid.
- Email must end with "@gmail.com".
- There must be at least one character before "@gmail.com".
- Special characters (@ . _) are allowed anywhere (no position check).
- If all above conditions pass → valid Gmail, else invalid.
def verify_Gmail(Gmail):
i=0
while i<len(Gmail):
current=Gmail[i]
i+=1
if current>="a" and current<="z":
continue;
elif current>="A" and current<="Z":
continue;
elif current>="0" and current<="9":
continue;
elif current=="@" or current=="." or current=="_":
continue;
else:
return False
if Gmail[-10:]=="@gmail.com":
return True
else:
return False
if verify_Gmail(input("Enter Your Gmail :")):
print("valid")
else:
print("invalid")
3.Mobile number validation :
- Allow only digits (0–9), '+' and space; reject anything else.
- If length = 10 → must be all digits and start with 6–9.
- If length = 13 → must start with "+91" and next digit must be 6–9.
- If length = 14 → must start with "+91 " and next digit must be 6–9.
- Otherwise → invalid mobile number.
def verify(mobnum):
index=0
while index<len(mobnum):
if mobnum[index]>="0" and mobnum[index]<="9":
index+=1
continue;
else:
return False
return True
def mobile(n):
i=0
while i<len(n):
if(n[i]>="0" and n[i]<="9") or (n[i]=="+") or (n[i]==" "):
i+=1
else:
return "characters and special charactors not allowed"
if len(n)==10:
if n[0]>="6" and n[0]<="9" and verify(n):
return "valid";
else:
return "incorrect"
if len(n)==13:
if n[0:3]=="+91":
if n[3]>="6" and n[3]<="9" and verify(n[3:]):
return "valid"
else:
return "incorrect"
return "First three number should like +91"
if len(n)==14:
if n[0:4]=="+91 ":
if n[4]>="6" and n[4]<="9" and verify(n[4:]):
return "valid"
else:
return "incorrect"
return "First four number should like +91 "
return "Please Enter Your valid Mobile Number"
print(mobile(input("Enter Your Mobile Number : ")));
