Python字符串方法|S2（len，count，center，ljust，rjust，isalpha，isalnum，isspace和join） _isalnum

下面的S3中介绍了一些字符串方法
字符串方法第1部分
本文讨论了更多方法
1. len()：-此函数返回长度的字符串。
【Python字符串方法|S2（len，count，center，ljust，rjust，isalpha，isalnum，isspace和join）】2. count(” string” , beg, end)：-此功能计数提到的发生子串整个字符串。此函数接受3个参数substring, 开始位置(默认为0)和结束位置(默认为字符串长度)。

# Python code to demonstrate working of # len() and count() str = "srcmini is for geeks"# Printing length of string using len() print ( " The length of string is : " , len ( str )); # Printing occurrence of "geeks" in string # Prints 2 as it only checks till 15th element print ( " Number of appearance of " "geeks" " is : " , end = "") print ( str .count( "geeks" , 0 , 15 ))

输出如下：

The length of string is :26 Number of appearance of geeks is : 2

3. center()：-此功能用于用字符将字符串括起来重复弦的两端多次。默认情况下, 字符为空格。有两个参数, 字符串和字符的长度。
4. ljust():-这个函数返回左移的原始字符串，在它的右边有一个字符。它向左调整字符串。默认字符为空格。它还接受两个参数，字符串的长度和字符。
5. rjust():-这个函数返回向左移动一个字符的原始字符串。它正确地调整了弦。默认字符为空格。它还接受两个参数，字符串的长度和字符。

# Python code to demonstrate working of # center(), ljust() and rjust() str = "srcmini"# Printing the string after centering with '-' print ( "The string after centering with '-' is : " , end = "") print ( str .center( 20 , '-' ))# Printing the string after ljust() print ( "The string after ljust is : " , end = "") print ( str .ljust( 20 , '-' ))# Printing the string after rjust() print ( "The string after rjust is : " , end = "") print ( str .rjust( 20 , '-' ))

输出如下：

The string after centering with '-' is : ---srcmini---- The string after ljust is : srcmini------- The string after rjust is : -------srcmini

6. isalpha()：-当字符串中的所有字符都为字母否则返回false。
7. isalnum()：-当字符串中的所有字符都为数字和/或字母的组合否则返回false。
8. isspace()：-当字符串中的所有字符都为空格否则返回false。

# Python code to demonstrate working of # isalpha(), isalnum(), isspace() str = "srcmini" str1 = "123"# Checking if str has all alphabets if ( str .isalpha()): print ( "All characters are alphabets in str" ) else : print ( "All characters are not alphabets in str" )# Checking if str1 has all numbers if (str1.isalnum()): print ( "All characters are numbers in str1" ) else : print ( "All characters are not numbers in str1" )# Checking if str1 has all spaces if (str1.isspace()): print ( "All characters are spaces in str1" ) else : print ( "All characters are not spaces in str1" )

输出如下：

All characters are alphabets in str All characters are numbers in str1 All characters are not spaces in str1

9. join()：-此功能用于加入序列在其自变量中提及的字符串。

# Python code to demonstrate working of # join() str = "_" str1 = ( "geeks" , "for" , "geeks" )# using join() to join sequence str1 with str print ( "The string after joining is : " , end = "") print ( str .join(str1))

输出如下：