Python learning-How to filter data based on criteria in lists, dictionaries, and collections

Check out the Python official documentation version 3.6 prior to learning about the following knowledge.

1, Range (start,stop,step) function. Start defaults to 0,step to take a number every few steps.

List[range (5)]=[0,1,2,3,4]

The integer within the generated range. List[range (1,5)]=[1,2,3,4]

List[range (1,5,2)]=[1,3]

2, Randint (b) generates a random integer between a B (including a B). A=randint (3,6) a=3|4|5|6

3. generate a list with a length of 10, where the range of each element in the list is between-10, and 10

Data=[randint ( -10,10) for X in range (10)]

I. Filtering the data in a list

1. Filtering function filter (function, list) filter (lambda x:x>=0,data)

2. List parsing [x for x in Data if x>=0] This method is more efficient and short.

Second, filter the data in the dictionary

Generates a random dictionary dict={x:randint (70,100) for x in range (1,11)} key (1-10), and value is a random number between 70 and 100.

{1:82, 2:87, 3:96, 4:74, 5:73, 6:93, 7:73, 8:84, 9:77, 10:100}

{k:v for k,v in Dict.items () if v>=90} (using the Items method in Python3, Python2 with the Iteritems method)

Third, filter the data in the collection

Generates a set s={x for X in range (10)}

Filter {x for x in S if x>6}

Python learning-How to filter data based on criteria in lists, dictionaries, and collections