Strings in Python

• The Purpose of this paper is to get required idea of methods of String in python in simplified way

• String is a collection of characters.

• Strings are immutable in python that means we can not change values of string but to create new string.

• we can access each character by their index

Methods:

• string.strip()

  This method will delete the trailing and leading spaces of string
  

  
      string = " yaswanth " #Notice there are spaces before and after the string
  
      name = string.strip()
  
      print(name) #output : 'yaswanth'
  

• string.split()

  This method is overloaded, if we don't give any arguments to split() it will split the string at spaces and returns the list of strings.

  if we give argument to it, it will split the string at that character and returns list of strings

  
  
          string = " hellow world "
  
          ls = string.split()
  
          print(ls) #output ['hellow','world']
  
          string = string.strip()
  
          ls = string.split('o)
  
          print(ls) #output ['hell','w w','rld']
  

• string.lower()

  It will convert the every alphabet in string to lower case

          string = 'YASWANTH'
  
          lower_case = string.lower()
  
          print(lower_case) #output 'yaswanth'
  

• string.upper()

  It will convert the every alphabet in string to upper case
  

          string = 'yaswanth'
  
          upper_case = string.upper()
  
          print(lower_case) #output 'YASWANTH'
  
  

• string.isdigit()

  It will return a boolean value, if entire string is number returns true, else returns false.
  

          string = '12345'
  
          print(string.isdigit()) #prints True
  
          string = ' 12345 ' #Notice there a space in front and back of string
  
          print(string.isdigit()) #prints False
  
  

• string.isupper()

  This will return true if all the alphabets of string are upper case else it will return false
  

  
          string = 'HELLO WORLD'
  
          print(string.isupper()) #prints TRUE
  
          string = 'Hello world'
  
          print(string.isupper()) #prints FALSE  
  
  

• string.islower()

  This will return true if all the alphabets of string are lower case else it will return false
  

  
          string = 'HELLO WORLD'
  
          print(string.isupper()) #prints FALSE
  
          string = 'hello world'
  
          print(string.isupper()) #prints TRUE
  

• string.join(iterable)

  This function takes the iterable as a argument

  This will join string to each item in the iterable and returns string

  
  
          string = 'hello'
  
          string = ' '.join(string)
  
          print(string) # prints 'h e l l o ' as output
  
  
  

• string.startswith('object')

  This function returns True if string starts with given object else returns False

  
  
          string = 'hello, I am Yaswanth'
  
          print(string.startswith('hello')) #returns True
  

• string.index('object')

  This function returns the start index of object in string
  

          string = 'hey! There'     
          print(string.index('There')) #returns 5
  

• string.isalpha()

  This function retuns boolean value. it will return True if all characters in string are alphabets else returns false.
  

          string = 'hello'
  
          print(string.isalpha()) #returns True
  
          string = '1 hello 2'
  
          print(string.isalpha()) #retuns False
  
  

• string.format(arg1,arg2..)

  This function is used to format a string by sending arguments to string which are not necessorly strings.

  Although we have string literal to do this work now it's always good to know legacy code
  

  
          name = 'yaswanth'
  
          age = 21
  
          print('my name is {}, my age is {}'.format(name,age))
  
          # prints 'my name is yaswanth, my age is 22'
  
  

References:

• Python Docs
• w3 Schools