1.change the case: To chance the format and styleย 
2.Find(): It is a method it accepts a Substring as a positional argument ,starting and ending arguments as a optional arguments
3.index():It works similar to find() and raise value error if Substring is not available
4.rfind(),rindex(): These are the methods work similar to find() and index() but performs search from end to the beginning
5.Stripping the Spaces:Strip method to trim left and right method ,lstrip to trim left side space and rstrip to trim right space
6.Split():which splits into sub strings by the given delimeter and returns the list of of Substrings
7.join():string that accepts an iterable object like list,tuple or set
8.count():used to check how many times a substring is existed within the string
9.replace():Accepts two arguments that are orginal and replacement substrings
10.format(): used to crteate a complex string with the result of identifiers and expressions etc...