Python基础——判断和循环

• 2020 年 1 月 16 日
• 笔记

判断

缩进代替大括号。

冒号（:）后换号缩进。

if

test=100  if test>50:      print('OK')  print('test')

if-elif-else

test=50  if test>200:      print('200')  elif test<100:      print('100')  else:      print('100-200')

列表

test1=[123,456,789]  if 123 in test1:      print('OK')

字典

test2={'hello':123,'world':456}  if 'hello' in test2:      print('OK')

循环

while

数值

test=0  while test<10:      print(test)      test+=1

集合

test1=set(['hello','world'])  while test1:      test2=test1.pop()      print(test2)

for

集合

test3=set(['hello','world'])  for t in test3:#相当于foreach      print(t)

列表

test4=[123,456,789]  for i in range(3):      print(test4[i])

test5=[123,456,789,34,5435,26,2362,262,26,5]  for i in range(len(test5)):      print(test5[i])

continue

test6=[11,12,13,14,15,16,17,18,19,20]  for i in test6:      if i%2==0:          print(i)      else:          continue      print(i)

break

test7=[12,13,14,15,16,17,18,19,20]  for i in test7:      if i%2==0:          print(i)      else:          break      print(i)