V2EX linwood
 linwood 最近的时间轴更新
linwood

linwood

V2EX 第 36282 号会员,加入于 2013-03-20 21:10:17 +08:00
19 S 99 B
linwood 最近回复了
2013-03-20 21:41:30 +08:00
回复了 ThunderEX 创建的主题 Python 应该用file.next()还是file.readline()?
如果你把一个file当做一个iterator使用的话,是可以使用使用next()方法的,通常可以放在循环中。会返回下一行或者抛出一个StopIteration异常。

但是next()和readline()不能混合使用。

从网上抄了一段代码:
#!/usr/bin/python

# Open a file
fo = open("foo.txt", "r")
print "Name of the file: ", fo.name

# Assuming file has following 5 lines
# This is 1st line
# This is 2nd line
# This is 3rd line
# This is 4th line
# This is 5th line

for index in range(5):
line = fo.next()
print "Line No %d - %s" % (index, line)

# Close opend file
fo.close()

并且,当时使用for line in file:这种用法的时候实际上就是调用的next方法。

所以,你在需要使用的readline的时候,可以使用next。但next使用范围更广。
这个应该属于逻辑推理吧,这不就是计算机的弱项么?
关于     帮助文档     自助推广系统     博客     API     FAQ     Solana     1052 人在线   最高记录 6679       Select Language
创意工作者们的社区
World is powered by solitude
VERSION: 3.9.8.5 15ms UTC 18:23 PVG 02:23 LAX 11:23 JFK 14:23
Do have faith in what you're doing.
ubao msn snddm index pchome yahoo rakuten mypaper meadowduck bidyahoo youbao zxmzxm asda bnvcg cvbfg dfscv mmhjk xxddc yybgb zznbn ccubao uaitu acv GXCV ET GDG YH FG BCVB FJFH CBRE CBC GDG ET54 WRWR RWER WREW WRWER RWER SDG EW SF DSFSF fbbs ubao fhd dfg ewr dg df ewwr ewwr et ruyut utut dfg fgd gdfgt etg dfgt dfgd ert4 gd fgg wr 235 wer3 we vsdf sdf gdf ert xcv sdf rwer hfd dfg cvb rwf afb dfh jgh bmn lgh rty gfds cxv xcv xcs vdas fdf fgd cv sdf tert sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf shasha9178 shasha9178 shasha9178 shasha9178 shasha9178 liflif2 liflif2 liflif2 liflif2 liflif2 liblib3 liblib3 liblib3 liblib3 liblib3 zhazha444 zhazha444 zhazha444 zhazha444 zhazha444 dende5 dende denden denden2 denden21 fenfen9 fenf619 fen619 fenfe9 fe619 sdf sdf sdf sdf sdf zhazh90 zhazh0 zhaa50 zha90 zh590 zho zhoz zhozh zhozho zhozho2 lislis lls95 lili95 lils5 liss9 sdf0ty987 sdft876 sdft9876 sdf09876 sd0t9876 sdf0ty98 sdf0976 sdf0ty986 sdf0ty96 sdf0t76 sdf0876 df0ty98 sf0t876 sd0ty76 sdy76 sdf76 sdf0t76 sdf0ty9 sdf0ty98 sdf0ty987 sdf0ty98 sdf6676 sdf876 sd876 sd876 sdf6 sdf6 sdf9876 sdf0t sdf06 sdf0ty9776 sdf0ty9776 sdf0ty76 sdf8876 sdf0t sd6 sdf06 s688876 sd688 sdf86