python - 检查字符串是否只是字母和空格 - Python

Question

试图让 python 返回一个字符串只包含字母和空格

string = input("Enter a string: ")

if all(x.isalpha() and x.isspace() for x in string):
    print("Only alphabetical letters and spaces: yes")
else:
    print("Only alphabetical letters and spaces: no")

我一直在尝试 please 结果是 Only alphabetical letters and spaces: no 我用 or 而不是 and，但那只满足一个条件。我需要满足这两个条件。也就是说，句子必须包含仅字母 和仅包含空格，但必须至少包含一种。它必须不包含任何数字。

对于 python 返回字母和空格只包含在字符串中，我在这里缺少什么？

Answer 1

一个字符不能既是字母又是空格。它可以是字母 或 空格。

要求字符串只包含字母和空格:

string = input("Enter a string: ")

if all(x.isalpha() or x.isspace() for x in string):
    print("Only alphabetical letters and spaces: yes")
else:
    print("Only alphabetical letters and spaces: no")

要求字符串至少包含一个字母和至少一个空格:

if any(x.isalpha() for x in string) and any(x.isspace() for x in string):

要求字符串至少包含一个字母，至少一个空格，并且只包含字母和空格:

if (any(x.isalpha() for x in string)
    and any(x.isspace() for x in string)
    and all(x.isalpha() or x.isspace() for x in string)):

测试:

>>> string = "PLEASE"
>>> if (any(x.isalpha() for x in string)
...     and any(x.isspace() for x in string)
...     and all(x.isalpha() or x.isspace() for x in string)):
...     print "match"
... else:
...     print "no match"
... 
no match
>>> string = "PLEASE "
>>> if (any(x.isalpha() for x in string)
...     and any(x.isspace() for x in string)
...     and all(x.isalpha() or x.isspace() for x in string)):
...     print "match"
... else:
...     print "no match"
... 
match