import random
from functools import reduce

#Define common functions and generate lists automatically
def getList():
    hList = list(range(5))
    return [key * random.randint(0,3) for key in hList] #Generate random number

#Define common functions to find the largest union in different lists
def getMaxSet(listA,listB):
    setA = set(listA) #Turn to set
    setB = set(listB)
    setAll = setA | setB #Seeking Union
    return list(setAll)#Turn to list

#Defining higher order functions
def highFunction(listA,listB,getMaxSet):
    return getMaxSet(listA,listB)

# Get two sets
listA = getList()
print("aggregate A:{}".format(listA))
listB = getList()
print("aggregate B:{}".format(listB))

# Get union of two sets
listC = getMaxSet(listA, listB)
print("aggregate A And set B Union:{}".format(listC))

#Call higher-order function
values = highFunction(listA,listB,getMaxSet)
print("Call higher-order function to get set A And set B Union:{}".format(values))

#map(f,Iterable):f;What to do, Iterable: Recyclable
def mapF(arg):
    return len(arg)

# Call built-in higher-order function map，Get the length of each string
test = ['python', 'tensorflow', 'keris', 'tensorboard', 'tensorflow', 'tensorflow', 'keris']
maps = list(map(mapF, test))
print("The length of each string is:{}".format(maps))

#reduce(f,Iterable):f;What to do, Iterable: Recyclable
def reduceF(arg1,arg2):
    return arg1 + arg2

# Call built-in higher-order function reduce，Sum the length of all strings
reduces = reduce(reduceF, maps)
print("The total length of the string is:{}".format(reduces))

# test and Operator sum strip()Remove string space operator
a = " a" and " a".strip()
b = "b " and "b ".strip()
c = " c " and " c ".strip()
print("test and Operator sum strip()Remove string space operator:a:{},b:{},c:{}".format(a,b,c))

# filter(f,Iterable):filter() Function is used to filter the sequence, filter out unqualified elements, and return a new list of qualified elements.
#It receives two parameters, the first is a function, the second is a sequence, each element of the sequence is passed to the function as a parameter for judgment, and then returns True or False，
#Will return True The elements of are placed in the new list.
# Filter the empty string and do not modify the data that meets the conditions
def del_empty(s):
    return s and s.strip() #strip()Used to remove characters specified at the beginning and end of a string (space or newline by default)
filterList = list(filter(del_empty, [" a", "", "b ", None, "v", " "]))
print(filterList)

#Basics sort()
print(sorted([36, 5, -12, 9, -21])) #Digital by size
print(sorted(["36", "5", "-12", "9", "-21"])) #String pressing ASCII code
#Advanced
print(sorted([36, 5, -12, 9, -21], key=abs))#Take absolute value first, and then sort (without affecting the original data)
print(sorted(['bob', 'about', 'Zoo', 'Credit'], key=str.lower, reverse=True)) #Convert to lowercase first, sort by transpose (do not affect the original data)