CODEWITHSUNDEEP
python
K.Vee.Shanker.
K.Vee.Shanker.

Reputation: 305

Restricting the User Input to Alphabets

I'm a technical writer learning python. I wanted to write a program for validating the Name field input,as a practise, restricting the the user entries to alphabets.I saw a similar code for validating number (Age)field here, and adopted it for alphabets as below:

import string

import re

r = re.compile(r'[a-zA-Z]+') 
print "WELCOME FOR NAME VERIFICATION. TYPE ALPHABETS ONLY!"
print raw_input("Your Name:")
x = r
if x == r:
    print x
elif x != r:
    print "Come on,'", x,"' can't be your name"
    print raw_input("Your Name:")
if 5<=len(x)<=10:
    print "Hi,", x, "!"
elif len(x)>10:
    print "Mmm,Your name is too long!"
elif len(x)<5:
    print "Alas, your name is too short!"

raw_input("Press 'Enter' to exit!")

I intend this code block to do two things. Namely, display the input prompt until the user inputs alphabets only as 'Name'. Then, if that happens, process the length of that input and display messages as coded. But, I get two problems that I could not solve even after a lot of attempts. Either, even the correct entries are rejected by exception code or wrong entries are also accepted and their length is processed.

Please help me to debug my code. And, is it possible to do it without using the reg exp?

Upvotes: 2

Views: 13481

Answers (3)

Shawabawa
Shawabawa

Reputation: 2597

I don't understand what you're trying to do with

x = r
if x == r:
    etc

That condition will obviously always be true.

With your current code you were never saving the input, just printing it straight out.

You also had no loop, it would only ask for the name twice, even if it was wrong both times it would continue.

I think what you tried to do is this:

import string
import re

r = re.compile(r'[a-zA-Z]+') 
print "WELCOME FOR NAME VERIFICATION. TYPE ALPHABETS ONLY!"
x = raw_input("Your Name:")

while not r.match(x):
    print "Come on,'", x,"' can't be your name"
    x = raw_input("Your Name:")

if 5<=len(x)<=10:
    print "Hi,", x, "!"
elif len(x)>10:
    print "Mmm,Your name is too long!"
elif len(x)<5:
    print "Alas, your name is too short!"

raw_input("Press 'Enter' to exit!")

Also, I would not use regex for this, try

while not x.isalpha():

Upvotes: 1

Serdalis
Serdalis

Reputation: 10489

One way to do this would be to do the following:

namefield = raw_input("Your Name: ")

if not namefield.isalpha():
    print "Please use only alpha charactors"

elif not 4<=len(namefield)<=10:
    print "Name must be more than 4 characters and less than 10"
else:
    print "hello" + namefield

isalpha will check to see if the whole string is only alpha characters. If it is, it will return True.

Upvotes: 0

user830639
user830639

Reputation:

If you're using Python, you don't need regular expressions for this--there are included libraries which include functions which might help you. From this page on String methods, you can call isalpha():

Return true if all characters in the string are alphabetic and there is at least one character, false otherwise.

I would suggest using isalpha() in your if-statement instead of x==r.

Upvotes: 2

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