我怎么能告诉一个字符串是否只包含使用正则表达式的python中的数字和空格

Question

I'm trying to write some script in python (using regex) and I have the following problem:

I need to make sure that a string contains ONLY digits and spaces but it could contain any number of numbers.

Meaning it should match to the strings: "213" (one number), "123 432" (two numbers), and even "123 432 543 3 235 34 56 456 456 234 324 24" (twelve numbers).

I tried searching here but all I found is how to extract digits from strings (and the opposite) - and that's not helping me to make sure weather ALL OF THE STRING contains ONLY numbers (seperated by any amount of spaces).

Does anyone have a solution?

If someone knows of a class that contains all the special characters (such as ! $ # _ -) it would be excellent (because then I could just do [^AZ][^az][^ special-class ] and therefore get something that don't match any characters and special symbols - leaving me only with digits and spaces (if I'm correct).

Answer 1

This code will check if the string only contains numbers and space character.

if re.match("^[0-9 ]+$", myString):
    print "Only numbers and Spaces"

Answer 2

The basic regular expression would be

/^[0-9 ]+$/

However is works also if your string only contains space. To check there is at least one number you need the following

/^ *[0-9][0-9 ]*$/

You can try it on there

Answer 3

Well I'd propose something that does not use regex :

>>> s = "12a 123"
>>> to_my_linking = lambda x: all(var.isdigit() for var in x.split())
>>> to_my_linking(s)
False
>>> s = "1244 432"
>>> to_my_linking(s)
True
>>> a = "123 432 543 3 235 34 56 456 456 234 324 24"
>>> to_my_linking(a)
True

In case you're working the lambda is just a simple way to make a one liner function. If we wrote it using a def , then it would look like this:

>>> def to_my_linking(number_sequence):
...     return all(var.isdigit() for var in number_sequence.split())
...