using try and regex in python

Question

I'd like to use a try/except statement for checking that a string consists of letters only. What is wrong with the following

class LetterError(Exception):
    pass

name = ""
while name=="":
    try:
        x = re.match(r'[a-zA-Z]',(input("Please enter a name: ")))
        raise LetterError
    except LetterError :
        print("Insert letters only")

Then you need to use at least `r'[a-zA-Z]+$'` with `re.match`. Then only raise the error `if not x`. — Wiktor Stribiżew, May 02 '17 at 10:10
You are using only one letter out of `[A-Za-z]`. Add `+` like this `[A-Za-z]+`. It means many letters. — Rahul, May 02 '17 at 10:10

score 0 · Answer 1 · answered May 02 '17 at 10:14

0

Your regex [a-zA-Z] will match only one character out of given range [a-zA-Z].

I suppose by name you mean multiple characters. Thus use [a-zA-Z]+ for matching multiple characters.

answered May 02 '17 at 10:14

Rahul

2,658
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score -1 · Accepted Answer · edited May 23 '17 at 11:54

-1

You are raising error in all case. You need to add a condition and also, you don't need your custom error. Regex from here https://stackoverflow.com/a/3617808/5567387

name = ""
while name == "":
    name = raw_input("Please enter a name: ")
    is_valid = re.match(r'^[a-zA-Z]+$', name)
    if not is_valid:
        name = ""

edited May 23 '17 at 11:54

Community

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1

answered May 02 '17 at 10:15

Zohaib Ijaz

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Have you tested it? There are multiple issues. – yeniv May 02 '17 at 10:17
The OP wanted to check if a string consists of letters only. The current solution would accept if the string has numbers in it e.g. if it is `abcd345` or `abcd5efgh`. – yeniv May 02 '17 at 10:33

using try and regex in python

2 Answers2