Python：如果单词包含数字

Question

I'm writing a function that will take a word as a parameter and will look at each character and if there is a number in the word, it will return the word

This is my string that I will iterate through 'Let us look at pg11.' and I want to look at each character in each word and if there is a digit in the word, I want to return the word just the way it is.

import string

def containsDigit(word):

    for ch in word:
        if ch == string.digits
        return word

Answer 1

if any(ch.isdigit() for ch in word):
    print word, 'contains a digit'

Answer 2

To make your code work use the in keyword (which will check if an item is in a sequence), add a colon after your if statement, and indent your return statement.

import string

def containsDigit(word):

    for ch in word:
        if ch in string.digits:
            return word

Answer 3

Why not use Regex?

>>> import re
>>> word = "super1"
>>> if re.search("\d", word):
...     print("y")
...
y
>>>

So, in your function, just do:

import re
def containsDigit(word):
    if re.search("\d", word):
        return word
print(containsDigit("super1"))

output:

'super1'

Answer 4

You are missing a colon:

for ch in word:
    if ch.isdigit(): #<-- you are missing this colon
        print "%s contains a digit" % word
        return word

Answer 5

Often when you want to know if "something" contains "something_else" sets may be usefull.

digits = set('0123456789')

def containsDigit(word):  
    if set(word) & digits:  
        return word

print containsDigit('hello')

Answer 6

If you desperately want to use the string module. Here is the code:

import string
def search(raw_string):
    for raw_array in string.digits:
        for listed_digits in raw_array:
            if listed_digits in raw_string:
                return True
    return False

If I run it in the shell here I get the wanted resuts. (True if contains. False if not)

>>> search("Give me 2 eggs")
True
>>> search("Sorry, I don't have any eggs.")
False

Code Break Down

This is how the code works

The string.digits is a string. If we loop through that string we get a list of the parent string broke down into pieces. Then we get a list containing every character in a string with'n a list. So, we have every single characters in the string! Now we loop over it again! Producing strings which we can see if the string given contains a digit because every single line of code inside the loop takes a step, changing the string we looped through. So, that means ever single line in the loop gets executed every time the variable changes. So, when we get to; for example 5. It agains execute the code but the variable in the loop is now changed to 5. It runs it agin and again and again until it finally got to the end of the string.