Python There are mainly 8 Type of data ：number（ Numbers ）、string（ character string ）、list（ list ）、tuple（ Tuples ）、dict（ Dictionaries ）、set（ aggregate ）、Boolean（ Boolean value ）、None（ Null value ）.
among Python There are six standard data types :
1、 character stringThere are three ways to declare strings ： Single quotation marks 、 Double and triple quotes （ Include three single quotes or three double quotes ）
>>> str1 = 'hello world'>>> str2 = "hello world">>> str3 = '''hello world'''>>> str4 = """hello world""">>> print str1hello world>>> print str2hello world>>> print str3hello world>>> print str4hello world2、 Numbers Python3 Three different numerical types are supported ：
integer (int)： It's usually called an integer or an integer , It's a positive or negative integer , Without decimal point .Python3 There is no limit to the size of an integer , Can be viewed as Long Type used , therefore Python3 No, Python2 Of Long type .
floating-point (float): Floating point type consists of integer part and decimal part , Floating point types can also be represented by scientific notation .
The plural ( (complex)): The plural consists of the real part and the imaginary part , It can be used a + bj, perhaps complex(a,b) Express , The real part of a complex number a Deficiency part of harmony b It's all floating point .
3、 listA list is a modifiable collection type , Its elements can be numbers 、string Isobasic type , It could be a list 、 Tuples 、 Collection objects such as dictionaries , It can even be a custom type . It is defined as follows ：
>>> nums = [1,2,3,4]>>> type(nums)<type 'list'>>>> print nums[1, 2, 3, 4]>>> strs = ["hello","world"]>>> print strs['hello', 'world']>>> lst = [1,"hello",False,nums,strs]>>> type(lst)<type 'list'>>>> print lst[1, 'hello', False, [1, 2, 3, 4], ['hello', 'world']]4、 Tuples Tuple types are the same as lists , It's also a sequence , Unlike the list , Tuples are immutable . Tuples are declared as follows ：
lst = (0,1,2,2,2)lst1=("hello",)lst2 = ("hello")print type(lst1) #<type 'tuple'> If there is only one element, add a comma after it Otherwise, it would be str type print type(lst2) #<type 'str'>5、 Dictionaries Dictionary is another variable container model , And can store any type of object . Each key value of the dictionary key=>value Yes, with a colon : Division , Comma between each key value pair , Division , The whole dictionary is enclosed in curly brackets {} in , The format is as follows ：
>>>dict = {'a': 1, 'b': 2, 'b': '3'}>>> dict['b']'3'>>> dict{'a': 1, 'b': '3'}6、 aggregate aggregate （set） Is an unordered sequence of non-repeating elements . You can use braces { } perhaps set() Function to create a collection .
Be careful ： To create an empty collection, you must use the set() instead of { }, because { } Is used to create an empty dictionary . Create format ：
a={'a','b','c','d'}b=set('abcdefabcd')c=set({'a':1,'b':2})d=set(['a','b','c','a'])print(a,type(a))print(b,type(b))print(c,type(c))print(d,type(d))# Running results {'c', 'd', 'b', 'a'} <class 'set'>{'f', 'e', 'b', 'c', 'd', 'a'} <class 'set'>{'b', 'a'} <class 'set'>{'c', 'b', 'a'} <class 'set'>
This is about Python This is the end of the article on data types . I hope it will be helpful for your study , I also hope you can support the software development network .
