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This article mainly introduces what the five standard data types of Python are and how to use the relevant knowledge, the content is detailed and easy to understand, the operation is simple and fast, and has a certain reference value, I believe you will have something to gain after reading this article on what the five standard data types of Python are and how to use them. Let's take a look.

Five standard data types of Python

Figures

String

List

Tuple

Dictionaries

I. figures

Immutable data type, stored value is numeric

1. Create objects and assign numeric values

Example:

> num1 = 1 > > num2 = 2 >

2. You can also use the de statement to delete some objects. The syntax of the del statement is:

> num1 = 1 > > num2 = 2 > > del num1 > print (num1) Traceback (most recent call last): File ", line 1, in NameError: name 'num1' is not defined deletes the object, which means that it has been removed from the inside and cannot be used again, otherwise an error will be reported.

3. Python supports four different numeric types: int (signed integers) long (long integers [can also be represented in octal and hexadecimal]) float (floating point real values) complex (complex)

In the specific use process, we also need to pay attention to:

When using long data types, both lowercase l and uppercase L can indicate long integer data, but it is recommended that uppercase L is preferred to avoid misrecognition.

A complex number includes an ordered pair represented as a + bj, where an is the real part and b is the real floating point number of the imaginary part of the complex.

String 1. The string in Python is defined as a set of consecutive characters between quotation marks.

Here both single quotation marks and double quotation marks can represent a string, but they cannot be mixed.

The string is an immutable data type and cannot be modified

Example:

> str = 'sssss' > str1 = "ssssss" > print (str, str1) sssss ssssss > str'sssss' > str1'ssssss' Note: if you do not use print strong format output under the interactive compiler, single quotation marks will be used by default, indicating that this is a subset of string 2 and string.

You can use the slice operator to make it available ([] and [:])

The beginning and end of a string whose index starts at 0 (- 1).

For example: str = 'abcdef' str [: 2] + str [2:] is actually a string str [0:2] with the same content as str, and the result is' ab', that is, no str before and after package [- 2str] here: > str [- 2str 1]'e' / here no package before and after citation > str [- 1]'f'/ slice or reference can be negative, 0 and-0 are the first letter on the left. The first bit on the right starts with-1, which usually reports an error if it exceeds the subscript, but it has been processed in python and returns the string concatenation operator of the empty character > 3 and the plus sign (+) sign when it goes out of bounds > > str1 ='a'> str2 ='b' > > str1+ str2'ab' > str1+'b''ab' > 'xs'+'xsx''xsxsx' >

In addition to the + sign, it can actually:

>

But you can't:

> str ='c'> > str'd' File "", line 1 str'd' ^ SyntaxError: invalid syntax >

This usage can be used to use a secondary operation when a line feed is entered when the character is long.

> str = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa''bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb' > > str'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb' > 4. The asterisk (*) indicates repeated operation.

For example:

> str'*4'strstrstrstr' >

You can use it.

III. List

Lists are the most common Python composite data types and are mutable data.

The list is separated by commas, and the data types stored are not required to be consistent.

To some extent, lists are similar to arrays in C, one difference between them is that the data that all belong to a list can be of different data types.

Values stored in a list can be asked ([] and [:]) using the slice operator.

The index starts at 0 and ends with-1 at the beginning and end of the list. The plus sign (+) sign list concatenation operator and the asterisk (*) operate repeatedly. For example:

> list = [1, list [5]'> list [0:2] [1] > > list [- 3 list] [5] > list*2 [1, 2, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5 'sfolk, 22222]

You can use append () to add elements

> list.append (34) > > print (list) [1, 2, 3, 4, 5, 3, 3, 34]

Nestible list

> st1 = [1meme2pr 3] > st2 = [1.2pr 1.3] > st3 = ['axiang pommel'] > st = [st1,st2,st3] > st [[1pr 2pr 3], [1.2pr 1.3], ['axie dagger']

List size and length can be changed

Use the del function or the slicing operation to change the length of the list, for example:

> > st [[1,2,3], [1.2,1.3,2.3], ['await,' baked,'c']] > del st [0] > st [[1.2,1.3,2.3], ['averse,' baked,'c']] > st [0:1] = [] > st [['await,' baked,'c']] > four tuples

Tuples are sequence data types similar to those in a list. The values of a tuple separated by several commas. Unlike lists, except that tuples are enclosed in parentheses (note that parentheses are optional).

> stu = (1) > stu1 = 1) > stu > stu1 (1) > stu1) >

The main difference between lists and tuples is that lists are enclosed in parentheses ([]) and their elements and sizes can be changed, while tuples in parentheses () cannot be updated. Tuples can be thought of as just reading lists. For example:

> stu = (1, most recent call last): File ", line 1, in TypeError: 'tuple' object does not support item assignment > stu*2 (1, stu*2) > > stu [0] 1 > stu [0:1] (1,) > > stu*2

Python dictionary is a hash phenotype.

Like associative arrays or hashes in Perl, they are made up of keys-

Composition of value pairs. The dictionary key can almost be of any Python type, but it is usually a number or string. The value can be an object of arbitrary Python.

> student1 = {'name':'zxb','sex':'man','age':'12'} > student1 {' name':'zxb','sex':'man','age':'12'} >

The dictionary consists of curly braces and brackets ({}), assigns values, and asks with square brackets ([]). For example:

> student1 ['age']' 12' > student1.keys () dict_keys (['name',' sex', 'age']) > student1.values () dict_values ([' zxb', 'man',' 12']) >

Sort dictionary elements

> sorted (student1) ['age',' name', 'sex'] this is the end of the article on "what are the five standard data types of Python and how to use them?" Thank you for reading! I believe you all have a certain understanding of the knowledge of "what are the five standard data types of Python and how to use them". If you want to learn more, you are welcome to follow the industry information channel.

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