Python String Methods 2

1. Python isalnum () method #检测字符串是否由字母和数字组成

Returns True if the string has at least one character and all characters are letters or numbers, otherwise False>>>'Hello'. Isalnum () True>>>'hello123'. Isalnum () True>>>'hello_123'. Isalnum () False>>>'The is string'. Isalnum () False>>>'Hello World'. Isalnum () False

View Code2. Python isalpha () method #检测字符串是否只由字母组成

Returns True if the string has at least one character and all characters are letters, otherwise False ' hello123 ' . Isalpha () False ' Hello World ' . Isalpha () False ' HelloWorld ' . Isalpha () True

View Code3. Python isdigit () method #检测字符串是否只由数字组成

returns True if the string contains only numbers otherwise False ' 12345 ' . IsDigit () True ' 12345a ' . IsDigit () False

View Code4. Python islower () method #检测字符串是否由小写字母组成

Returns True if the string contains at least one case-sensitive character, and all of these (case-sensitive) characters are lowercase, otherwise False ' 2hello ' . Islower () True ' _hello ' . Islower () True ' Hello ' . Islower () False ' _hello ' . Islower () False

View Code5. Python isnumeric () method #检测字符串是否只由数字组成. This method is only for Unicode objects

' u ' prefix >>> u'123456'. IsNumeric () True>>> u' 123a456 ' . IsNumeric () False>>> u'123_456'. IsNumeric () False 

View Code6. Python isspace () method #检测字符串是否只由空格组成

returns True if the string contains only spaces, otherwise False '    ' . Isspace () True '   ' # \ t True ' _    ' . Isspace () False '   1  '. Isspace () False

View Code7. The Python Istitle () method #检测字符串中所有的单词拼写首字母是否为大写, and the other letters are lowercase

Returns True if all the words in the string are spelled with the first letter uppercase, and the other letter is lowercase, otherwise False ' Hello World ' . Istitle () True ' Hello World ' . Istitle () False ' HEllo World ' . Istitle () False ' Hello World123 ' . Istitle () True

View Code8. Python isupper () method #检测字符串中所有的字母是否都为大写

returns True if the string contains at least one case-sensitive character, and all of these (case-sensitive) characters are uppercase, otherwise False ' HELLO World ' . Isupper () True ' HELLO World ' . Isupper () False

View Code9. Python Join () method #用于将序列中的元素以指定的字符连接生成一个新的字符串

 >>> seq = ( " a  " ,  " b  " ,  " c  "  )  >>>  " Span style= "COLOR: #800000" >+   " .join (seq)   " a+b+c   " >>> "   hello   " .join (seq)   " a hellob helloc   " 

View CodeThe Python len () method #返回对象 (character, list, tuple, etc.) length or number of items

" Hello World ">>> len (str)11>>> l = [1,2,3,4,5,6]>>> len (l)6

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Python String Methods 2