Python string processing Daquan.

The Python string string is a common data type in Pyhton, and we can use quotation marks to create a string. It's easy to create a string, not to mention it. Python accesses the value in the string ghost uncle in a concise use of design purposes, at the time of design. There is no single character in the string.  All characters exist as strings.  Python accesses the string from which you can slice operations. Here's a chestnut.

1>>> str1='Yuanchongyang'2>>> Str1[4:9]3 'Chong'4>>> str1='Yuan Chongyang Good'5>>> Str[:3]6>>> Str1[:3]7 'Yuan Chongyang'8>>>

Python string Update the so-called string update with or string slices and string concatenation, here is only one example, specifically to see the string slices, and string concatenation.

1 >>> str1=' I love Zai Weiwei '2 >>> str2=' I am yuan Chongyang  '3 >>> str1=str2[2:5]+str1[1:5]4 >>> str1 5 ' yuan Chongyang love Zai Weiwei '

Python transfer character

Python string operator Subscript instance variable a value is String ' Hello ', b variable value ' Python '

Python string formatting python supports the output of a formatted string, although this may be a very complex expression with a knife, but the most basic use is to insert a value into a string with the string format of%s. The string format character is similar to the C language.

1 Print (' I am%s' %str1) 2 I am Chong Yeung

%c	Formatting characters and their ASCII code
%s	formatting strings
%d	formatting integers
%u	Formatting an unsigned integer
%o	Formatting an unsigned octal number
%x	formatting unsigned hexadecimal numbers
%x	Format unsigned hexadecimal number (uppercase)
%f	Format floating-point numbers to specify the precision after a decimal point
%e	Format floating-point numbers with scientific notation
%E	function with%e, format floating-point numbers with scientific notation
%g	Shorthand for%f and%e
%G	Shorthand for%f and%E
%p	Format the address of a variable with hexadecimal number

Python's string built-in function string method is the method that is slowly added from Python1.6 to 2.0, which implements most of the methods of the string module, such as the following table, which lists the methods currently supported in string literals.

Method	Description
String.capitalize ()	Capitalize the first character of a string
String.center (width)	Returns the center of the original string and fills the new string with a space of length width
String.count (str, beg=0, End=len (String))	Returns the number of occurrences of STR in a string, if beg or end specifies that the number of STR occurrences in the specified range is returned
String.decode (encoding= ' UTF-8 ', errors= ' strict ')	Decodes a string in the encoded format specified by encoding, if an error defaults to a ValueError exception unless errors specifies ' ignore ' or ' replace '
String.encode (encoding= ' UTF-8 ', errors= ' strict ')	Encodes a string in the encoding format specified by encoding, if an error defaults to a ValueError exception unless errors specifies ' ignore ' or ' replace '
String.endswith (obj, beg=0, End=len (String))	Checks whether the string ends with obj, or returns False if beg or end specifies whether to end with obj in the specified range, or True if it is.
String.expandtabs (tabsize=8)	Turns the tab symbol in string strings to a space, and the default number of spaces for the tab symbol is 8.
String.find (str, beg=0, End=len (String))	Detects if STR is contained in a string, and if beg and end specify a range, the check is contained within the specified range, and returns 1 if the index value is returned.
String.index (str, beg=0, End=len (String))	Just like the Find () method, only if STR does not report an exception in string.
String.isalnum ()	If the string has at least one character and all characters are letters or numbers, return Return True, otherwise False
String.isalpha ()	Returns True if the string has at least one character and all characters are letters. otherwise returns False
String.isdecimal ()	Returns True if the string contains only a decimal number, otherwise False.
String.isdigit ()	Returns True if the string contains only a number, otherwise False.
String.islower ()	Returns True if the string contains at least one case-sensitive character, and all of these (case-sensitive) characters are lowercase, otherwise False
String.isnumeric ()	Returns True if the string contains only numeric characters, otherwise False
String.isspace ()	Returns True if the string contains only spaces, otherwise False is returned.
String.istitle ()	Returns True if string is heading (see Title ()), otherwise False
String.isupper ()	Returns True if the string contains at least one case-sensitive character, and all of these (case-sensitive) characters are uppercase, otherwise False
String.Join (seq)	Merges all the elements in the SEQ (the string representation) into a new string, using string as a delimiter
String.ljust (width)	Returns the left alignment of an original string and fills the new string with the width of length with a space
String.Lower ()	Converts all uppercase characters in a string to lowercase.
String.lstrip ()	Truncate the left space of a string
String.maketrans (Intab, Outtab])	The Maketrans () method is used to create a conversion table of character mappings, for the simplest invocation of two parameters, the first argument is a string that represents the character that needs to be converted, and the second argument is the target of the string representation of the transformation.
Max (str)	Returns the largest letter in the string str .
Min (str)	Returns the smallest letter in the string str .
String.partition (str)	A bit like the combination of find () and split (), from the first position where Str appears, divide the string into a 3-element tuple (STRING_PRE_STR,STR,STRING_POST_STR), if string STR is not included in the STRING_PRE_STR = = string.
String.Replace (str1, str2, Num=string.count (STR1))	Replace the str1 in string with the str2, if NUM is specified, the replacement is no more than num times.
String.rfind (str, Beg=0,end=len (String))	Similar to the Find () function, it is just looking from the right.
String.rindex (str, Beg=0,end=len (String))	Similar to index (), but starting from the right.
String.rjust (width)	Returns the right alignment of the original string and fills the new string with the width of the length with a space
String.rpartition (str)	Similar to the partition () function, it is just looking from the right.
String.rstrip ()	Removes a space at the end of a string string.
String.Split (str= "", Num=string.count (str))	Slice string with a delimiter of STR, if NUM has a specified value, only the NUM substring is delimited
String.splitlines (Num=string.count (' \ n '))	Returns a list that contains rows as elements, separated by rows, and if num specifies that only num rows are sliced.
String.startswith (obj, Beg=0,end=len (string))	Checks whether the string starts with obj, returns True, or False. If beg and end specify a value, the check is within the specified range.
String.strip ([obj])	Execute Lstrip () and Rstrip () on string
String.swapcase ()	Flip the case in a string
String.title ()	A string that returns "header", meaning that all words start with uppercase and the remaining letters are lowercase (see istitle ())
String.translate (str, del= "")	Converts a string of characters according to the table given by STR, which contains 256 characters, The characters to filter out are placed in the Del parameter
String.upper ()	Convert lowercase letters in string to uppercase
String.zfill (width)	Returns a string of length width, the original string is right-aligned, and the front padding is 0
String.isdecimal ()	The Isdecimal () method checks whether a string contains only decimal characters. This method exists only in Unicode objects.

Python string processing Daquan.