Python that you don't want to give up

Python section of this section (data type)

1 Basic data types

Digital:
int: grade, age, grade, ID number, QQ number, mobile number
level=10
Float type: Height, weight, salary, temperature, price
height=1.81
salary=3.3

String str: Enclosed in quotation marks (single, double, three), consisting of a string of characters
Use (descriptive data): Name, gender, address, education, password: alex3714
Name= ' Egon '

Value:
First, make it clear that the string as a whole is a value, except that it is special:
There is no character type in Python, the string is made up of a string of characters, you want to remove the character from the string, or you can do so by subscript.

Name: Gets the value that is the whole of the string
NAME[1]: Get the character that is the second place

string concatenation:
　　　

>>> msg1= ' Hello ' >>> msg2= ' world ' >>>>>> msg1 + msg2 ' Hello World ' >>> res= MSG1 + msg2>>> Print (res) Hello world>>> msg1*3 ' Hellohellohello '

List: contained within [], separated by commas
Use (save multiple values, can be modified): hobbies, equipment, girlfriends
hobby=[' play ', ' eat ', ' sleep ']
Method:
Hobby.append
Hobby.remove
Operation:
View:

>>> girls=[' Alex ', ' WSB ', [' Egon ', ' YSB ']]>>> girls[2][' Egon ', ' YSB ']>>> girls[2][0]

Increase
Girls.append (Element)
Delete
Girls.remove (Element)
Del girls[index of elements]
Modify
girls[0]= ' ALEXSB '

Dictionary dict: defined in {}, comma-separated, each element in the form of a key:value

Student_info= "" "Name:alexsex:noneage:81hobby:zsb00 zsb1 zsb2 zsb3" "#name sex Age hobbystudent_info=[' Alex ', none,81, [' zsb0 ', ' zsb1 ', ' zsb2 ', ' Zsb30 '] STUDENT_INFO[3][2]

Dictionary:
Purpose: Store multiple values, which is the same as the list, and the value can be any data type
Characteristics: Each value is a one-to-one correspondence, i.e. key, which emphasizes that key must be
Immutable types: Strings, numbers

student_info={' age ': Bayi, ' name ': ' Alex ', ' sex ': None, ' hobbies ': [' zsb0 ', ' zsb1 ', ' zsb2 ', ' Zsb30 ']}

Operation:
View

>>> student_info={... ' Age ': Bayi,... ' Name ': ' Alex ',... ' Sex ': None,... ' Hobbies ': [' zsb0 ', ' zsb1 ', ' zsb2 ', ' Zsb30 '] ...} >>>>>> student_info[' age ']81>>> student_info[' hobbies ' [' zsb0 ', ' zsb1 ', ' zsb2 ', ' Zsb30 '] >>> student_info[' hobbies '][2] ' ZSB2 '

Increase
student_info[' stu_id ']=123456

Delete
Del student_info[' stu_id ']

Modify
student_info[' name ']= ' ALEXSB '


Boolean: True False
Purpose: Used to judge

>>> pinfo={' name ': ' Oldboymei ', ' age ': +, ' sex ': ' Female '}>>>>>>>>> pinfo[' age '] > 50true>>> pinfo[' sex '] = = ' Female ' True

Python that you don't want to give up