这 5 个 Python 特性，后悔没早知道

add_func = lambda z: z ** 2is_odd = lambda z: z%2 == 1multiply = lambda x,y: x*y
aList = list(range(10))print(aList)# [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

# Syntax of list comprehension[ expression(x) for x in aList if optional_condition(x) ]

print(list(map(add_func, aList)))print([x ** 2 for x in aList])# [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]# [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
print(list(filter(is_odd, aList)))print([x for x in aList if x%2 == 1])# [1, 3, 5, 7, 9]# [1, 3, 5, 7, 9]

a, b, c, d = aList[0:4]print(f'a = {a}, b = {b}, c = {c}, d = {d}')# a = 0, b = 1, c = 2, d = 3
a, *b, c, d = aListprint(f'a = {a}, b = {b}, c = {c}, d = {d}')# a = 0, b = [1, 2, 3, 4, 5, 6, 7], c = 8, d = 9

numList = [0, 1, 2]engList = ['zero', 'one', 'two']espList = ['cero', 'uno', 'dos']print(list(zip(numList, engList, espList)))# [(0, 'zero', 'cero'), (1, 'one', 'uno'), (2, 'two', 'dos')]
for num, eng, esp in zip(numList, engList, espList):    print(f'{num} is {eng} in English and {esp} in Spanish.')# 0 is zero in English and cero in Spanish.# 1 is one in English and uno in Spanish.# 2 is two in English and dos in Spanish.

Eng = list(zip(engList, espList, numList))Eng.sort() # sort by engLista, b, c = zip(*Eng)
print(a)print(b)print(c)# ('one', 'two', 'zero')# ('uno', 'dos', 'cero')# (1, 2, 0)

upperCase = ['A', 'B', 'C', 'D', 'E', 'F']lowerCase = ['a', 'b', 'c', 'd', 'e', 'f']for i, (upper, lower) in enumerate(zip(upperCase, lowerCase), 1):    print(f'{i}: {upper} and {lower}.')# 1: A and a.# 2: B and b.# 3: C and c.# 4: D and d.# 5: E and e.# 6: F and f.

def gen(n):    # an infinite sequence generator that generates integers >= n    while True:        yield n        n += 1        G = gen(3)     # starts at 3print(next(G)) # 3print(next(G)) # 4print(next(G)) # 5print(next(G)) # 6

conda create -n venv pip python=3.7  # select python versionsource activate venv...source deactivate