Beginner Python (12)--higher Order function

Beginner Python (12)--higher Order function

Beginner Python, mainly finishing some of the learning points, This is the Higher-order Function.

#-*-coding:utf-8-*-    " "higher order functions: functions that can be used as parameters are called Higher-order functions." "  #function as parameterdefF (x):returnx*x#the map function is a built-in function, meaning that the list of the second argument is in the F function#The final result is a listPrintMap (f,[1,2,3,4,5])  #the reduce function is a built-in function, meaning that the sequence of the second parameter acts to the value of the Add function#the result is calculated as a summation, and the final result is a numberdefAdd (x, y):returnx+yPrintReduce (add,[1,2,3,4,5,6])  #give a number on each position of an integer to get the integer  deffn (x, y):returnx*10+yPrintReduce (fn,[1,2,3,4,5])    #string goto int  PrintReduce (fn,map (int,'12345'))    defStr2Int (s):deffn (x, y):returnx*10+yreturnreduce (fn,map (INT,S))PrintStr2Int ('123456')  " "the procedure for calling the above function Is: 1. Get reduce (fn,map (int, ' 123456 ')) 2. Get reduce (fn,[1,2,3,4,5,6]) 3. Get reduce (x*10+y,[1,2,3,4,5,6]) 4. Get 123456" "  defStr2int2 (s):returnReduceLambdax,y:x*10+Y,map (INT,S))PrintStr2int2 ('1234567')      #SortPrintSorted'313568')  PrintSorted ((1,8,4,2,5))  PrintSorted ([9,8,7,6,5,4,3])  PrintSorted (['name',' age','Sex','Address'])  #Sorted is also a high-order function, so it can also transfer functions to change the sorting algorithm#ReversedefInverted_order (x, y):ifX>Y:return-1elifx<Y:return1Else:          return0PrintSorted ((1,8,4,2,5), inverted_order)#changing the string sorting algorithm#the above string sorting is based on the ASCII code to determine the size#because uppercase letters are smaller than the ASCII code of lowercase letters,#but in general, we're all in alphabetical order.#Let's change the algorithm, ignoring the Case.  defAlphabet (s1,s2): L1=s1.lower () L2=S2.lower ()ifL1 <l2:return-1elifL2 <l1:return1Else:          return0PrintSorted (['name',' age','Sex','Address'],alphabet)" "the ' function as the return value actually involves the form of a function as a return value just before the string is transferred to int" "    defSum (*args): sum=0 forNinchArgs:sum+=NreturnsumPrintSum (1,2,3,4,5)    #converted to return function form  defSum_pack (*args):defsum (): sum1=0 forNinchArgs:sum1+=Nreturnsum1returnSum g= Sum_pack (1,2,3,4,5)  Printg#<function sum at 0x0134c0f0>#g output as function, want to print result to call functionPrintg ()" "definition of closure: word function automatically gets the variables and parameters of the parent function it's MINE. and each call returns a function that is not the same object" "G1= Sum_pack (1,2,3,4,5) G2= Sum_pack (1,2,3,4,5)  PrintG1==g2

Beginner Python (12)--higher Order function