Python练习-- List Comprehensions

#!/usr/bin/python
# -*- coding: utf-8 -*-

print('List Comprehensions!!')

mylist=[x*x for x in range(1,11)]
print(mylist)

mylist2 = [x*x for x in range(1,10) if x%2 == 0]
print(mylist2)

mylist3 = [m+n
4000
for m in 'ABC' for n in 'XYZ']
print(mylist3)

import os
mylist4 =[d for d in os.listdir('.')]
print(mylist4)

d = {'x': 'A', 'y': 'B', 'z': 'C' }
for k,v in d.items():
print(k,'=',v)

mylist5 = [k+'='+v for k,v in d.items() ]
print(mylist5)

L = ['Hello', 'World', 'IBM', 'Apple']
lowerL = [s.lower() for s in L]
print(lowerL)

L2 = ['Hello', 'World', 18, 'Apple', None]
lowerL2 = [s.lower() for s in L2 if isinstance(s,str)]
print(lowerL2)