Summary of Python work

The following methods are seldom used and other solutions are used to summarize some other colleagues ' skills.

1 How to automatically generate lists, plus a condition to filter

[x for X in range (ten) if X>5]

Try a dictionary in the afterlife

D = {X:randint (60,100) for x in range (1,21)}//Randint need to import package

From random import Randint

Filter the dictionary method with iteration

{k:v for k,v in D.iteritems () if v>90}//Iteritems () Py3 also renamed

D.items ()

How to name each element in no group

Studen = ("Xsy", +, "13575665", "[email protected]")

Such data is saved as a tuple to save memory, and access can be

#name

STUDEN[0]

#age

STUDEN[1]

The above method accesses, but the code is more, the number represents what is not intuitive

Python mimics the C-Write enumeration method to resolve: 1, define some constants first

NAME =0

Age = 1

SEX = 2

EMAIL = 3

Advanced definition Methods

Name,age,sex,emae = Range (4)

The following examples use

Print (Student[name])//

If studen[age]>=18k

If student[sex] = = "Male"

Method two, construct with class

From collections Import Namedtuple
Student = Namedtuple ("Student", [' Name ', ' age ', ' sex ', ' xx '])
s = Student ("Jim", +, ' male ', ' [email protected] ')
Print (S.name)
Print (Isinstance (s,tuple))//true, meaning can be used in a group of places can use this method

Number of occurrences of the list element

From random import Randint

[Randint (0,20) for X in Rnage (30)]//will generate 30 random numbers now we want to count to a dictionary such as {8:2,7:6} 8 appears 2 times, 7 appears 6 times. This way

D =[randint (0,20) for X in Rnage (30)],

Eventually become

c= {2:6,6:4 ...}.}

Complete the function code as follows

From random import Randint
D =[randint (0,20) for X in range (30)]
c = Dict.fromkeys (d,0)
For x in D:
    C[x]+=1
Print (c)

Summary of Python work