Python：如何继续在文件中的同一行写入？

Question

Here is a snippet:

f = open("a.txt","r")
paragraph = f.readlines()
f1 = open("o.txt","w")
for line in paragraph:
    f1.write(line)

Here, how can I manage to write continuosly on the same line in o.txt?
For example, a.txt :

Hi,   
how  
are   
you?

Then o.txt should be:

Hi, how are you?

Thanks in advance.

Answer 1

You need to strip the lines then join and write to file :

with open("a.txt","r") as in_f,open("o.txt","w") as out_f: 
    out_f.write(' '.join(in_f.read().replace('\n','')))

Also as a more pythonic way for use with statement to dealing with files.

Or better :

with open("a.txt","r") as in_f,open("o.txt","w") as out_f: 
    out_f.write(' '.join(map(str.strip(),in_f))

or use a list comprehension :

with open("a.txt","r") as in_f,open("o.txt","w") as out_f: 
    out_f.write(' '.join([line.strip() for line in in_f])

Answer 2

remove new line char using rstrip

f = open("a.txt","r")
paragraph = " ".join(map(lambda s: s.rstrip('\n'), f.readlines()))
f1 = open("b.txt","w")
f1.write(paragraph)

Answer 3

try:
    with open('a.txt') as in_fh, open('o.txt', 'w') as out_fh:
        out_fh.write(' '.join(in_fh.read().split('\n')))
except IOError:
    # error handling

Answer 4

This occurs because Python reads the entire line, including the new-line character represented as \\n in python. The string in your example would result in an array like:

['Hi,\n', 'how\n', 'are\n', 'you?']

To solve this you need to remove the trailing \\n from each line, but beware that the last line might not contain a \\n so you cant just remove the last character of each line. There are pre-made methods built in to python to help you remove white-space characters (like new-line \\n and space " " ) from the beginning and the end of a string.

The official documentation can be a bit daunting, but finding and using information from documentation is probably one of the most important skills in the field of computing. Look at the official documentation and see if you find any useful methods in the string class. https://docs.python.org/3/library/stdtypes.html#str.strip

Answer 5

I found a solution. Here it goes. Basically using the replace() .

f = open("a.txt","r")
paragraph = f.readlines()
f1 = open("o.txt","w")
for line in paragraph:
    line = line.replace("\n"," ")
    f1.write(line)

Other methods are welcome! :)