String common operations
str.capitalize () first letter capitalized
str.casefold () all lowercase become more powerful, you can also perform many locations
str.lower () becomes all lowercase
str.center () with parameter string bracket width and the contents center, parameters representative of the length, the default blank filled, or filled with a character, optional
str.count () parentheses parameters ( 'query character', query start position, end position) count the number of parameters that appear within brackets in the string
str.encode coding
str.decode decoding
str.endswith () with parameters a parameter bracket ending
str.startswith () with parameters in parentheses for the beginning of the parameter
str.find () brackets with parameters based on index lookup to find the front to back, find the first after acquiring its position. ( 'Character query' query start position, end position) is not found -1
str.index () brackets with parameters look not found error function in accordance with the subscript supra Find
str.format () parentheses formatting parameters placeholder string {name} as replacing a specified value
str.format_map brackets with parameters passed in the value format () function is a dictionary format supra
str.isalnum () determines whether a string contains only letters and numbers are not False Ture