列表生成式

# 自动生成 1 2 3
l=list(range(1,4))
print(l)
#求 1*1  2*2  3*3
l2=[]
for x in range(1,4):
    l2.append(x*x)
print(l2)
# 简化
print([x * x for x in range(1, 4)])
# 求 x*x中的偶数
print([x * x for x in range(1, 4) if x % 2 == 0])
# 求双层循环
print([m + n for m in 'ABC' for n in 'XYZ'])
# 字典中打印key=value
d = {'x': 'A', 'y': 'B', 'z': 'C' }
for k, v in d.items():
  print(k, '=', v)