Question

我想替换包含patternB的行中的字符串，如下所示：

从：

some lines
line contain patternA
some lines
line contain patternB
more lines

为：

some lines
line contain patternA
some lines
line contain patternB xx oo
more lines

我有这样的代码：

inputfile = open("d:\myfile.abc", "r")
outputfile = open("d:\myfile_renew.abc", "w")
obj = "yaya"
dummy = ""
item = []

for line in inputfile:
    dummy += line
    if line.find("patternA") != -1:
        for line in inputfile:
            dummy += line
            if line.find("patternB") != -1:
                item = line.split()
                dummy += item[0] + " xx " + item[-1] + "\n"
                break
outputfile.write(dummy)

它不会替换包含＆＃34; patternB＆＃34;正如所料，但在它下面添加一个新行，如：

some lines
line contain patternA
some lines
line contain patternB
line contain patternB xx oo
more lines

我的代码怎么处理？

Answer 1

您可以使用str.replace：

s = '''some lines
line contain patternA
some lines
line contain patternB
more lines'''

print(s.replace('patternB', 'patternB xx oo'))

Answer 2

最简单的将是： 1.将所有文件读入字符串 2.调用string.replace 3.将字符串转储到文件

Answer 3

当然是，因为你在for循环的开头附加了行，然后在“if”语句中再次添加修改后的版本。另外，为什么检查模式A，如果你对待的是你对待其他一切？

inputfile = open("d:\myfile.abc", "r")
outputfile = open("d:\myfile_renew.abc", "w")
obj = "yaya"
dummy = ""
item = []

for line in inputfile:
    if line.find("patternB") != -1:
        item = line.split()
        dummy += item[0] + " xx " + item[-1] + "\n"
    else:
        dummy += line
outputfile.write(dummy)

Answer 4

如果你想逐行保持迭代器（对于一个大文件）

for line in inputfile:
    if line.find("patternB") != -1:
        dummy = line.replace('patternB', 'patternB xx oo')
        outputfile.write(dummy)
    else:
        outputfile.write(line)

这比其他响应慢，但可以进行大文件处理。

Answer 5

这应该有用

import os

def replace():

    f1 = open("d:\myfile.abc","r")
    f2 = open("d:\myfile_renew.abc","w")
    ow = raw_input("Enter word you wish to replace:")
    nw = raw_input("Enter new word:")
    for line in f1:
        templ = line.split()
        for i in templ:
            if i==ow:
                f2.write(nw)
            else:
                f2.write(i)
        f2.write('\n')
    f1.close()
    f2.close()
    os.remove("d:\myfile.abc")
    os.rename("d:\myfile_renew.abc","d:\myfile.abc")

replace()

在不添加新行的情况下替换字符串？

5 个答案: