appendix cstring operators and methods (continuedmethod center(width[fillchar]returns str count(sub[start[end]]int encode([encoding[errors]]bytes endswith(suffix[start[end]]bool expandtabs([tabsize]str find(sub[start[end]]int format(*args**kwargss index(sub[start[end]]str int isalnum(bool isalpha(bool isdecimal(bool isdigit(bool isidentifier(bool islower(bool comments returns centered in string of length width padding is done using the specified fill character (default is spacereturns the number of non-overlapping occurrences of substring sub in string [start:endoptional arguments start and end are interpreted as in slice notation encodes using the codec registered for encoding encoding defaults to the default encoding errors may be given to set different error handling scheme default is 'strictmeaning that encoding errors raise unicodeencodeerror other possible values are 'ignore''replaceand 'xmlcharrefreplaceas well as any other name registered with codecs register_error that can handle unicodeencodeerrors returns true if ends with the specified suffixfalse otherwise with optional starttest beginning at that position with optional endstop comparing at that position suffix can also be tuple of strings to try returns copy of where all tab characters are expanded using spaces if tabsize is not givena tab size of characters is assumed returns the lowest index in where substring sub is foundsuch that sub is contained within [start:endoptional arguments start and end are interpreted as in slice notation return - on failure like find(but raise valueerror when the substring is not found returns true if all characters in are alphanumeric and there is at least one character in sfalse otherwise returns true if all characters in are alphabetic and there is at least one character in sfalse otherwise returns true if there are only decimal characters in sfalse otherwise returns true if all characters in are digits and there is at least one character in sfalse otherwise returns true if is valid identifier according to the language definition returns true if all cased characters in are lowercase and there is at least one cased character in sfalse otherwise (continuedthis copy belongs to 'acha