1. The syntax and usage of the isspace function

①Syntax: string.isspace()

②Usage: Determine whether the string contains only null characters.

Return two necessary conditions for True

①The string contains at least one character

②The string is a null character, and the null character can be a space (' '), a horizontal tab ('\t'), a carriage return ('\r'), a line feed ('\n'), or a page feed ('\f') etc.

In other cases, the return result is False

2. Instance of isspace

(1) Simple usage

"""isspace函数"""
"".isspace()
#输出结果为False 解释：因为该字符串没有字符所以返回为False

' '.isspace()
#输出结果为True 解释：因为该字符串只有空格字符' '字符所以返回为True

'\n'.isspace()
#输出结果为True 解释：因为该字符串只有换行符'\n'所以返回为True 

'\t'.isspace()
#输出结果为True 解释：因为该字符串只有横向制表符'\t'所以返回为True 

'\r'.isspace()
#输出结果为True 解释：因为该字符串只有回车符'\r'所以返回为True 

'\f'.isspace()
#输出结果为True 解释：因为该字符串只有换页符'\f'所以返回为True 

'\f\r\t '.isspace()
#输出结果为True 解释：因为该字符串只有多种空字符'\f\r\t '所以返回为True

(2) Used in conjunction with the if conditional function

Determine whether a string contains only null characters, if yes, return bingo, otherwise return rejectedly.

str = '    '
if str.isspace() is True:
    print('bingo')
else:
    print('dejectedly')

#输出结果为dejectedly

(3) Combined use with input function and if conditional function

Determine whether an input string contains only null characters, if yes, return bingo, otherwise return rejectedly.

str = input('请输入目标字符串')
if str.isspace() is True:
    print('bingo')
else:
    print('dejectedly')


#若输入的值为：     #空字符
#输出结果为：bingo
#若输入的值为：\f\r\t 
#输出结果为：bingo
#若输入的值为：hjk
#输出结果为：dejectedly

(3) Combined use with for traversal function and if conditional function

Determine whether several strings in a list contain only null characters, if yes, return bingo, otherwise return rejectedly.

#定义str
list = [' ','\f','\f\n','hjka ']
for str in list:
    if str.isspace() is True:
        print('bingo')
    else:
        print('dejectedly')

#输出结果为：bingo
#bingo
#bingo
#dejectedly

For specific input function usage, please refer to the article: python's input function usage

For specific usage of if judgment statement, please refer to: usage and examples of if conditional statement in python

Python judges whether a string is all empty characters - usage and examples of the isspace function