如何使用python摆脱字符串中的\\ n和\\ r

Question

I have written a python(2.7) program to retreive data from a table in a database and copy it into a csv file. There are various data in non-printable format(unicode) which contain \\n, \\r. Because of \\n, \\r I am not able to retreive the data as it is in the table.

I have tried the following

str.replace('\n','').replace('\r',' ')
str.replace('\n','\\n').replace('\r', '\\r')

but it did not work out

csv code

 cur.execute('select * from db.table_name)
with open('test.csv','w') as csv_file:
    csv_writer=csv.writer(csv_file)
    for row in cur:
        print "row = ", count
        count = count + 1
        newrow=[];
        for index in range(0, len(row)):
            value= row[index]
            if(type(row[index])is str):
                 value=row[index].replace("\n"," ").replace("\r"," ")
            newrow.append(value)
       csv_writer.writerow(newrow)

Answer 1

str.replace()返回一个新字符串，因此您必须将其分配给原始字符串才能进行更改：

s = s.replace('\n','').replace('\r','')

Answer 2

Unicode has external serialized representations such as UTF-8 and UTF-16 and language-dependent internal implementations such as WCHAR. Your database read appears to have given you a UTF-16 serialized version of the string and all you have to do is decode it. You certainly don't want to remove the \\r and \\n because they are part of the multi-byte sequence and not really carriage return or newline at all.

As a simple example, I can remove all the the database and looping stuff and just work with the string you posted:

>>> value = '\r\xaeJ\x92>J\xe7\x1d\n\x89`\xc6\xf8\x9c<\x18'
>>> decoded = value.decode('UTF-16')
>>> print repr(decoded)
u'\uae0d\u924a\u4a3e\u1de7\u890a\uc660\u9cf8\u183c'
>>> print decoded
긍鉊䨾ᷧ褊왠鳸ᠼ
>>> 

Answer 3

You can use regular expression to simplify your code:

For example:

import re
s = "Salut \n Comment ca va ?"
s = re.sub("\n|\r|\t", "",  s)

print(s)

Output will be as:

Salut Comment ca va ?

Answer 4

您只需在输入末尾添加.strip（）即可完成此操作，例如：n = input（）。strip（）它将删除字符串中的所有“ / r”