如何仅从输入中排除数字，标点符号？ 蟒蛇

Question

Is there any way to make a rule, where answer to the input may be only String or string+numeric value without punctuation marks/space. So that will look like.

Insert first name:  …
… name: 5363737 - **not allowed**
… name: Bird1 ! - **not allowed**
… name: Bird1 - **allowed**

Answer 1

Whatever you are "inserting" with might have its own validation functions, but if not, its a straightforward regular expression to filter with.

import re

inserts = [
    'aBC123',
    'ABC 123',
    'i like pie.',
    '123abc',
]

for i in inserts:
    if re.match('^[a-zA-Z]+[0-9]*$', i):
#   if re.match('^[a-zA-Z0-9]*$', i):   #leaving my old error visible as a testament to the importance of reading the spec carefully.
        print('insert', i)
        # call insert function
    else:
        print('NOT inserting', i)
        # do whatever

Answer 2

    Code:

     or i in "5363737","Bird1 !", "Bird1", "Bird1923812", "Bird":

        mo = re.match(r'([A-Za-z]+[0-9]*)$',i)

        if mo:
            print("allowed {}".format(mo.group(0)))
        else:
            print("not allowed {}".format(i))

    not allowed 5363737
    not allowed Bird1 !
    allowed Bird1
    allowed Bird1923812
    allowed Bird

# if needed, as stated in the comment  char+number+char, number+char, 
# number+char+number.
for i in "536cat3737","Bird1 !", "Bird1", "Bird1923812bird", "Bird","777Bird":

    mo = re.match(r'([A-Za-z]*[0-9]+[A-Za-z]+|\d+[A-Za-z]+\d+)$',i)

    if mo:
        print("allowed {}".format(mo.group(0)))
    else:
        print("not allowed {}".format(i))

Answer 3

Without re module:

from string import letters, digits
from itertools import chain

while True:
    user_input = input('Insert first name: ')
    if all(c in digits for c in user_input) or #invalid if only numbers   
       any(c not in chain(letters,digits) for c in user_input): #invalid if something else than letters+numbers
        print 'name: ' + user_input + '** not allowed **'
    else:
        print 'name: ' + user_input + '** allowed **'
        break