Python：替换 .txt 文件中的字符串

Question

import os, sys
pandaFile = open("panda.txt", "w")
pandaRead = pandaFile.read()

if "NOON" in pandaRead:
    print("Enter a noon:")
    noon = input()
    str.replace("NOON",noon)

if "ADJECTIVE" in pandaRead:
    print("Enter an adjective:")
    adjective = input()
    str.replace("ADJECTIVE", adjective)

if "VERB" in pandaRead:
    print("Enter and verb:")
    verb = input()
    str.replace("VERB",verb)

newcontent = open("panda.txt","w")

我的目标是打开文件“Panda.txt”文件。如果有ADVERB、VERB或NOON，用用户输入替换这些字符串。并重写“panda.txt”文件. 我的错误代码是： pandaRead = pandaFile.read() io.UnsupportedOperation: not readable 我在 Windows Vista Home 版本上使用带有 Python 3.4 的 Sublime text 2。

Answer 1

您的代码中有几个错误。我会向你解释它们，但为了进一步发展，请始终保留Python reference website 以查看你调用的方法的用法。

以下是我必须从您的代码中处理的各种错误：

• 打开您的文件，specifying you want to read it pandaFile = open("panda.txt", "w")
• 不要打印您的提示，but use the input argument to set a prompt print("Enter a noon:") noon = input()
• 应该在 String 实例上调用 replace 方法，而不是类，and it returns the new value str.replace("NOON",noon)
• 实际上写你的新字符串inside the opened file newcontent = open("panda.txt","w")

考虑到这些，以下代码示例是（我假设）您打算执行的操作：

import os , sys

# With is a special bloc statement,
# closing your variable pandaFile at the end of the bloc.
with open("panda.txt", "r") as pandaFile:
    pandaRead = pandaFile.read()

if "NOON" in pandaRead:
    noon = input("Enter a noon:")
    pandaRead = pandaRead.replace("NOON", noon) 

if "ADJECTIVE" in pandaRead:
    adjective = input("Enter an adjective:")
    pandaRead = pandaRead.replace("ADJECTIVE", adjective)

if "VERB" in pandaRead:
    verb = input("Enter and verb:")
    pandaRead = pandaRead.replace("VERB",verb)

with open("panda.txt", "w") as pandaFile:
    pandaFile.write(pandaRead)