Python:从文件读取和替换字符串(带有特殊字符)时出错 [英] Python: Error while reading and replacing String(with special characters) from file

问题描述

a.json文件:

{
  "a": "b",
  "key": "graph: \"color\" = 'black' AND \"api\" = 'demo-application-v1' nodes",
  "c": "d"
}

以下我尝试过的代码:

string_to_be_replace = "abcd"
string_to = "graph: \"color\" = 'black' AND \"api\" = 'demo-application-v1' nodes"
string_to_be_identified = "\"color\" = \'black\' AND \"api\" = \'demo-application-v1\'"
string_to_be_identified1 = '"color" = \'black\' AND "api" = \'demo-application-v1\''

print string_to_be_identified
print string_to_be_identified1
print string_to.replace(string_to_be_identified1,string_to_be_replace)
print string.replace(string_to, string_to_be_identified,string_to_be_replace)

输出:

颜色" =黑色"和"api" ="demo-application-v1"

"color" = 'black' AND "api" = 'demo-application-v1'

颜色" =黑色"和"api" ="demo-application-v1"

"color" = 'black' AND "api" = 'demo-application-v1'

图:abcd节点

图:abcd节点

这可以正常工作，并且可以按预期替换字符串，但是

This is working fine and replacing string as expected but

不是我尝试以下方法时

方法1:

1. 以读取模式打开文件，

1. Open file in a read mode,

逐行获取并替换字符串

with open(path + '/a.json', 'r') as file:
    read_lines = file.readlines()
    for line in read_lines:
        print line.replace(string_to_be_identified,string_to_be_replace)
file.close()

输出:

{

"a":"b"，

"key":"graph:\" color \"='黑色'AND \" api \"= "demo-application-v1"节点"，

"key": "graph: \"color\" = 'black' AND \"api\" = 'demo-application-v1' node",

"c":"d"

}

方法2:

1. 以读取模式打开文件

1. Open file in read mode,

由于文件a.json具有JSON数据，请加载json文件，然后将json对象转换为JSON字符串，然后替换它.

Since the file a.json has JSON data, get json file loaded, convert json object to JSON-string and then replace it.

代码:

 with open(path + '/a.json', 'r') as file:
    loadedJson = json.load(file)
    print "z: " + str(loadedJson).replace(string_to_be_identified, string_to_be_replace)
file.close()

输出:

z:{u'a':u'b'，u'c':u'd'，u'key':u'graph:"color" = \'black \'AND "api" = \'demo-application-v1 \'节点'}

z: {u'a': u'b', u'c': u'd', u'key': u'graph: "color" = \'black\' AND "api" = \'demo-application-v1\' node'}

方法3:

我认为JSON字符串中的Unicode字符可能会造成问题，因此将Unicode字符串转换为普通字符串，然后尝试替换字符串

I assume Unicode character in JSON string might be creating a problem so converted Unicode string to normal string and then tried to replace string

代码:

def byteify(input):
    if isinstance(input, dict):
        return {byteify(key): byteify(value)
                for key, value in input.iteritems()}
    elif isinstance(input, list):
        return [byteify(element) for element in input]
    elif isinstance(input, unicode):
        return input.encode('utf-8')
    else:
        return input

with open(path + '/a.json', 'r') as file:
    loadedJson = json.load(file)
    js = byteify(loadedJson)
    print "a: " + str(js).replace(string_to_be_identified, string_to_be_replace)

输出:

a:{'a':'b'，'c':'d'，'key':'graph:"color" = \'black \'AND"api" = \'demo-application-v1 \'节点'}

a: {'a': 'b', 'c': 'd', 'key': 'graph: "color" = \'black\' AND "api" = \'demo-application-v1\' node'}

• python版本:2.7.15
• 使用其中一个SO答案中的字节码.
• JSON文件很大，无法进行手动搜索和替换.
• 在上面的示例中仍尝试在python中的'和'没有区别.
• python version:2.7.15
• using byteify code from one of the SO answer.
• JSON file is big and cannot do the manual search and replace.
• There is no difference in ' and " in python still tried in above example.

推荐答案

虽然我当然不建议使用任何类型的不了解上下文的搜索&替换为JSON之类的层次结构，您的主要问题是，您在JSON文件中搜索的字符串已转义了引号(文字\字符)，因此如果您要进行纯文本处理，则也必须考虑这些问题搜索.您可以使用原始字符串或添加反斜杠表示自己，例如:

While I certainly do not recommend any sort of context-unaware search & replace in a hierarchical structure like JSON, your main issue is that the string you're searching for in your JSON file has escaped quotations (literal \ characters) so you have to account for those as well if you want to do plain text search. You can use either raw strings or add the backslashes yourself, something like:

str_search = r"graph: \"color\" = 'black' AND \"api\" = 'demo-application-v1'"
# or, if you prefer to manually write down the string instead of declaring it 'raw':
# str_search = "graph: \\\"color\\\" = 'black' AND \\\"api\\\" = 'demo-application-v1'"
str_replace = "abcd"

with open("/path/to/your.json", "r") as f:
    for line in f:
        print(line.replace(str_search, str_replace))

对于您的JSON，这将产生:

Which, for your JSON, will yield:

{

  "a": "b",

  "key": "abcd nodes",

  "c": "d"

}

(print添加的其他新行).

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