python中read，readline，和readlines的区别 并逐行输出，,python中有神奇

python中read，readline，和readlines的区别 并逐行输出，,python中有神奇

python中有神奇的三种读操作：read、readline和readlines

read() ?： 一次性读取整个文件内容。推荐使用read(size)方法，size越大运行时间越长

readline() ?：每次读取一行内容。内存不够时使用，一般不太用

readlines() ? ：一次性读取整个文件内容，并按行返回到list，方便我们遍历

下面看代码：

#!/usr/bin/python# -*- coding: utf-8 -*-import linecachef = open("a.txt")lines = f.read()print lines#for i in lines:#    print i#    print "==="print (type(lines))f.close()print 35*"="fr = open("a.txt")r = fr.readline()print(type(r))#print rwhile r:    print r,    r = fr.readline()    print "rrr=",rfr.close()print 35*"="frs = open("a.txt")rls = frs.readlines()print(type(rls))print rlsfor i in rls:    print i,frs.close()# 直接输出第二行test2 = linecache.getline("a.txt", 2)print ""print 35*"="print test2

运行结果如下：

weiruoyuwangxitongweironghanweixitiantiankaixin<type ‘str‘>===================================<type ‘str‘>weiruoyurrr= wangxitongwangxitongrrr= weironghanweironghanrrr= weixiweixirrr= tiantiankaixintiantiankaixin rrr= ===================================<type ‘list‘>[‘weiruoyu\n‘, ‘wangxitong\n‘, ‘weironghan\n‘, ‘weixi\n‘, ‘tiantiankaixin‘]weiruoyuwangxitongweironghanweixitiantiankaixin ===================================wangxitong

参考了其他的文章：
https://www.cnblogs.com/yun1108/p/8967334.html
https://blog.csdn.net/weixin_41656968/article/details/80205717

python中read，readline，和readlines的区别 并逐行输出