Python data Type--number, string

The Python language is a strongly typed language and is a dynamic language that automatically checks the type of data during run time, so Python does not have to define variable types.

Python variable assignment:

A = 10b = 100c = List or a,b,c = 10,100,list

Python has five standard data types:

• Numbers (digital)
• String (String)
• List (lists)
• Tuple (tuple)
• Dictionary (dictionary)

Number (numeric):

Python supports four different numeric types:

• int (signed integral type)
• Long (longer integer [can also represent octal and hexadecimal])
• Float (float type)
• Complex (plural)

Numeric Type conversions:

int (x) converts x to integer type

STR (x) converts x to string type

Long (x), float (x), complex (x), list (x), tuple (x), Chr (x), UNICHR (), Hex (x), Oct (x) ...

String (String):

There is no character data type in Python, and a single character is a string type

The necessary conditions for equality of two strings are: equal lengths and equal characters at each corresponding position

Attribute: Non-mutable type

Common built-in methods:

String.Join (seq) merges all elements in the SEQ into a new element with Str as a delimiter

String.upper () converts all letters in a string to uppercase

String.Lower () converts all letters in a string to lowercase

String.swapcase () Flips the case of letters in a string

String.find (' str ' [, Beg=0,end=len (String)]) checks if STR exists in string, yes, returns TRUE or 0, otherwise returns false or not 0, "[]" inside the optional, default check entire string

String.index (' str ' [, Beg=0,end=len (String)]) is similar to the String.find command but does not present an error

String.count (' str ', [Beg=0,end=len (String)]) returns the number of STR occurrences in a string

String.Replace (' old ', ' new ' [, NUB]) replaces the old in the string with new, specifying the maximum number of conversions nub, which is the default transform all

String.Split (' str ' [, NUB]) splits a string with str as a string, specifying the number of splits, by default splitting all

Max (String) returns the largest character in Str

Min (String) returns the smallest character in Str

1. Links to Strings

A = ' abc ' b = ' def ' c = a+b or c = ' abc ' def ' #能够自动的将 ' abc ' and ' Def ' are connected together

2. Comparison of strings (CMP)

The CMP method compares two objects and returns an integer based on the result. CMP (x, y) if x< y, the return value is negative if x>y returns a positive value.

A = ' abc ' b = ' ABCD ' cmp (a B)

Python data Type--number, string