PYTHON map函数的应用

>>> list(map(int, ['12','-2','0']))
[12, -2, 0]
>>> list(map(len, ['hello','world']))
[5, 5]
>>> list(map(lambda s:s[::-1], ['hello','world']))
['olleh', 'dlrow']
>>> list(map(lambda n:(n,n**2,n**3), range(2,6)))
[(2, 4, 8), (3, 9, 27), (4, 16, 64), (5, 25, 125)]
>>> list(map(lambda t:t[0]*t[1], zip(range(2,5),range(3,9,2))))
[6, 15, 28]

a1 = ['12','-2','0']
a2 = ['hello','world']
a3 = ['hello','world']
a11 = []
a22 = []
a33 = []
a44 = []
for k in a1:
    a11.append(int(k))
for k in a2:
    a22.append(len(k))
for k in a3:
    a33.append(k[::-1])
i = 1
for k in range(2,6):
    a44.append((pow(k,i),pow(k,i + 1),pow(k,i + 2)))
print a11
print a22
print a33
print a44

print(list(map(int,['12','-2','0'])))

print(list(map(len, ['hello', 'world'])))

print(list(map(lambda x: x[::-1], ['hello', 'world'])))

print(list(map(lambda x:(x,x**2,x**3),range(2,6))))

print(list(map(lambda x:x[0]*x[1],zip(range(2,5),range(3,9,2)))))