Python 5.7

First, the basic data type supplement

#数据类型的补充
#元祖tuple, if there is an element in it and there is no comma, the data type is the type of the unique element.
# tu = ([[+]) #tu里面只有一个列表, without commas. The data type is list.
# Print (Tu,type (TU))
# tu = ([[+)], #里面虽然只有一个元素, but followed by a comma. or the Ganso type.
# Print (Tu,type (TU))
#for Loop, it is best not to iterate through the elements in the list or dictionary, changing the size of the list and dictionary. Will go wrong.
#解决办法, list, reverse loop, so it doesn't change the size of the list.
# li = [' Liujj ', ' xiaol ', ' jisp ')# for I in range (Len (LI) -1,-1,-1): #range顾头不顾腚, so the tail is 0-1=-1,len () peso is 1 more, so Len ()-1, when Len () as the tail,
# if I% 2 = = 1: #如果从0开始循环, Len () does not need-1.
# Li.pop (i)
# Print (LI)
#解决办法, dictionary, put the key you want to delete into a list, loop the list, and then delete the dictionary.
# dic = {' K1 ': ' v1 ', ' K2 ': ' v2 ', ' K3 ': ' V3 ', ' name ': ' Alex '}
# lis = []# for I in DIC:
# if ' K ' in I:
# lis.append (i)
# for M in Lis:
# Dic.pop (M)
# Print (DIC)
#tuple-->list list (TU) tuple (list)
#dic-->list List (DIC): All Keys---> list (Dic.keys ())
# All Values--->list (dic.values ())
# all key-value pairs (a pair of ganso in the list)--->list (dic.items ())
#set-->list List (set ())
#dict. Fromkeys (the element that precedes the split, the unique value corresponding to each element)
# dic = Dict.fromkeys (' abc ', 66)
# Print (DIC)
#False: 0, ", [], {}, ()

Two, set

#the increase of the collection#1.add#set = {' Liujj ', ' jiasp ', ' Jiaxl '}#set.add (' Cat ')#print (set)#2.update First Split and then add#set.update (' ABCDE ')#print (set)#the deletion of the collection#1.remove Delete by element#set.remove (' Jiaxl ')#print (set)#2.pop is randomly deleted and the returned value is the deleted element. #print (Set.pop ())#print (set)#3.del#4.clear Empty list: Set ()#the collection of search#only for one

collection of additions and deletions check

Iii. the relationship of the set

# the intersection of the   collection:&the set of intersection# Collections: |    The difference set of the Union # Set:-   difference# Set's inverse intersection: ^  symmetric_difference  # subset of collections: <  return value is true or false. Issubset# collection of superset: >    issuperset

orthogonal of Inverse cross subsets of the difference

Four, the depth copy

#Depth Copy#1. Assign a value. One change to the other, must be assigned first, the small data pool itself is the same memory address, so no need to assign value. #Li = [1, 2, 3]#Li2 = Li#li.append (#set2跟着set1变化)#print (LI,LI2)#2. Shallow copy. The first layer is independent, the second layer and above is the same memory address, is followed by change. #li1 = [1, 2, 3, [' Liujj ', ' jiasp ']#Li2 = li1.copy ()#li1[3].append (' Jiaxl ') #第二层增加, so the second layer in the LI2 also increases#print (LI1,LI2)#Li1.append (4)#print (LI1,LI2)#3. Deep copy,import copy/copy.deepcopy (table name). #不管第几层都是完全独立的. #Import Copy#Li2 = copy.deepcopy (li1)#Li1.append (a)#print (LI1,LI2)#li1[3].append (' xial ')#print (LI1,LI2)#4. The list of slices also belongs to-----> shallow copy.#Li2 = li1[:]#li1.append (in)#print (LI1,LI2)#li1[3].append (' lang ')#print (LI1,LI2)

Depth Copy

Python 5.7