Question

我想知道是否可以使用.isnumeric（）或.isdigit（）之类的方法来检查字符串是否具有特殊字符。如果没有，我该如何使用正则表达式进行检查？我只找到有关检查它是否包含字母或数字的答案。

Answer 1

检查任何不是字母数字的字符，例如：

any(not c.isalnum() for c in mystring)

Answer 2

尝试一下：

special_characters = ""!@#$%^&*()-+?_=,<>/""
s=input()
# Example: $tackoverflow

if any(c in special_characters for c in s):
    print("yes")
else:
    print("no")
 
# Response: yes

Answer 3

使用string.printable（doc）：

text = 'This is my text with special character (?)'

from string import printable

if set(text).difference(printable):
    print('Text has special characters.')
else:
    print("Text hasn't special characters.")

打印：

Text has special characters.

编辑：仅测试ASCII字符和数字：

text = 'text%'

from string import ascii_letters, digits

if set(text).difference(ascii_letters + digits):
    print('Text has special characters.')
else:
    print("Text hasn't special characters.")

Answer 4

假定空格不算作特殊字符。

def has_special_char(text: str) -> bool:
    return any(c for c in text if not c.isalnum() and not c.isspace())


if __name__ == '__main__':
    texts = [
        'asdsgbn!@$^Y$',
        '    ',
        'asdads 345345',
        '12?3123',
        'hnfgbg'
    ]
    for it in texts:
        if has_special_char(it):
            print(it)

输出：

asdsgbn!@$^Y$
12?3123

Answer 5

在寻找更好的解决方案时，这是一种不理想但可行的方法：

special_char = False
for letter in string:
    if (not letter.isnumeric() and not letter.isdigit()):
        special_char = True
        break

更新：尝试此操作，它可以查看字符串中是否存在正则表达式。显示的正则表达式适用于任何非字母数字字符。

import re
word = 'asdf*'
special_char = False
regexp = re.compile('[^0-9a-zA-Z]+')
if regexp.search(word):
    special_char = True

Answer 6

您可以像这样简单地使用字符串方法isalnum()：

firstString = "This string ha$ many $pecial ch@racters"
secondString = "ThisStringHas0SpecialCharacters"
print(firstString.isalnum())
print(secondString.isalnum())

这将显示：

False
True

如果您想了解更多关于here的信息。

Answer 7

Geeksforgeeks有一个使用正则表达式的很好的例子。

源-> https://www.geeksforgeeks.org/python-program-check-string-contains-special-character/ 考虑的特殊字符-> [@_！＃$％^＆*（）<>？/ \ |} {〜：]

# Python program to check if a string 
# contains any special character 

# import required package 
import re 

# Function checks if the string 
# contains any special character 
def run(string): 

    # Make own character set and pass  
    # this as argument in compile method 
    regex = re.compile('[@_!#$%^&*()<>?/\|}{~:]') 

    # Pass the string in search  
    # method of regex object.     
    if(regex.search(string) == None): 
        print("String is accepted") 

    else: 
        print("String is not accepted.") 


# Driver Code 
if __name__ == '__main__' : 

    # Enter the string 
    string = "Geeks$For$Geeks"

    # calling run function  
    run(string)

如何检查字符串是否有任何特殊字符？

7 个答案: