1. function returns multiple values:
1) If the function returns multiple values, the returned values are placed in a tuple
def say (): = 1 = 2 = 3 return= say ()print( RES)>>> (1, 2, 3)
2) function if you return multiple values, you can use multiple variables to receive each
def say (): = 1 = 2 = 3 return= say ()print(res1) #>>>1print(res2) # >>>2 Print (RES3) # >>>3
2, Lambda: anonymous function, function is simple, use only once, do not need to define
Lambda x:x+1 # before the colon is the return value, the colon is followed by the function body, and the function's processing logic Print(res (1))> >> 2
3. List-generated (list)
for in range (1,101,2-inif i%2==1] # or write like this print(l)>>>[1, 3, 5, 7, 9 ...]
if the form outside of the list generation is ():L is not a list , but a generator
for inch if i%2==1)print(l) #L is a generator #print (l.__next __ ()) #生成器调用一次取一个值for in L: print(i)> >> <generator Object <genexpr> at 0x00bfd8c8>>>>1 3 5 7 9 ...
# each time the generator loops, it calculates only one element per rule, in memory, than the list save memory
#list is to put all the elements in memory.
4, three-dimensional expression
A = 5= 4ifelse b # ternary expression print= 5 = 4if a>B: = aelse: = b Print(c)
5, the dictionary is unordered, directly to the dictionary sort does not exist. First, turn the dictionary into a list and sort
#sorted (): Automatically loops through the elements inside a two-dimensional array
D = {'a'75A'b': 2,'C': 3}Print(D.items ())#get a two-dimensional arrayres = sorted (D.items (), key=LambdaX:x[0])#The key value of the key= dictionary, sortedRes= Sorted (D.items (), key=LambdaX:X[1])#sort based on the value of the dictionaryPrint(RES)>>> Dict_items ([('b', 2), ('a', 5), ('C', 3)])>>> [('a', 5), ('b', 2), ('C', 3)]
To loop, take multiple:
L = [[1,2,3],[3,4,5],[5,6,7]] for in L: #a,b,c is 3, Each of the above small list contains 3 elements? Print(a,b,c)
6, when defining the function, tell others what type of argument should be passed
def is_float (S:STR): Pass
Lambda, list-generated, dictionary-to-list ordering