python中for、while語(yǔ)句后的else代碼塊是怎樣的

#今天學(xué)習(xí)下在#for或者while之后進(jìn)行的#else操作#定義一個(gè)listmy_list = [1, 2, 3, 4, 5]for i in my_list:  print(i)else:  print('執(zhí)行else模塊')#當(dāng)執(zhí)行完for循環(huán)，會(huì)執(zhí)行else代碼塊#打印結(jié)果為：#1#2#3#4#5#執(zhí)行else模塊#當(dāng)我們打斷for循環(huán)時(shí)，else就不會(huì)執(zhí)行for i in my_list:  print(i)  if i == 3:    breakelse:  print('執(zhí)行else模塊')#結(jié)果為：#1#2#3#接下來(lái)的情況會(huì)執(zhí)行else，#因?yàn)閒or沒(méi)有被打斷：for i in my_list:  print(i)  if i == 6:    breakelse:  print('執(zhí)行else模塊')#運(yùn)行結(jié)果略!#while循環(huán)的例子：i = 1while i <=5:  print(i)  i += 1else:  print('執(zhí)行while后的else語(yǔ)句') #使用break打斷語(yǔ)句:i = 1while i <=5:  print(i)  i += 1  if i == 3:    breakelse:  print('執(zhí)行while后的else語(yǔ)句')
#接下來(lái)看一個(gè)for...else的函數(shù)例子:def find_index(to_search,target):  for i,value in enumerate(to_search):    if value == target:      break  else:    return None  return i#定義一個(gè)list names = ['yale','tbag','test']index = find_index(names,'test')print('索引位置是:',index)#索引位置是: 2index_new = find_index(names,'John')print('索引位置是:',index_new)#索引位置是: None

12345執(zhí)行else模塊
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12345執(zhí)行else模塊
12345執(zhí)行while后的else語(yǔ)句
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索引位置是: 2索引位置是: None