在 Python 2.7 中替换字符串中的 '\\n'

Question

This is my file.txt:

Egg and Bacon;
Egg, sausage and Bacon
Egg and Spam;
Spam Egg Sausage and Spam;
Egg, Bacon and Spam;

I wanna convert the newLine '\\n' to ' $ '. I just used:

f = open(fileName)
text = f.read()      
text = text.replace('\n',' $ ')
print(text)

This is my output:

$ Spam Egg Sausage and Spam;

and my output must be like:

Egg and Bacon; $ Egg, sausage and Bacon $ Egg ...

What am I doing wrong? I'm using #-*- encoding: utf-8 -*-

Thank you.

Answer 1

It is possible that your newlines are represented as \\r\\n . In order to replace them you should do:

text.replace('\r\n', ' $ ')

---

For a portable solution that works on both UNIX-like systems (which uses \\n ) and Windows (which uses \\r\\n ), you can substitute the text using a regex:

>>> import re
>>> re.sub('\r?\n', ' $ ', 'a\r\nb\r\nc')
'a $ b $ c'
>>> re.sub('\r?\n', ' $ ', 'a\nb\nc')
'a $ b $ c'

Answer 2

You can use splitlines.

lines = """Egg and Bacon;
Egg, sausage and Bacon
Egg and Spam;
Spam Egg Sausage and Spam;
Egg, Bacon and Spam;"""

print(" $ ".join(lines.splitlines()))
Egg and Bacon; $ Egg, sausage and Bacon $ Egg and Spam; $ Spam Egg Sausage and Spam; $ Egg, Bacon and Spam;

Or simply use rstrip and join on the file object without reading all into memory:

with open("in.txt") as f: 
    print(" $ ".join(line.rstrip() for line in f))
    Egg and Bacon; $ Egg, sausage and Bacon $ Egg and Spam; $ Spam Egg Sausage and Spam; $ Egg, Bacon and Spam;

Which is a much more efficient solution than reading all the file into memory and using a regex. You should also always use with to open your files as it closes them automatically.

rstrip will remove \\n \\r\\n etc..

In [41]: s = "foo\r\n"
In [42]: s.rstrip()
Out[42]: 'foo'    
In [43]: s = "foo\n"    
In [44]: s.rstrip()
Out[44]: 'foo'

Answer 3

text = text.replace('\\n', '')