I am writing a list (simple[]) to a file using writelines() and I need each item from the list to be on a new line in the file. I am using the following code:
file_path_simple = r'[path_redacted]\tx_list_simple.txt'
with open(file_path_simple, 'w') as fp:
for i in simple:
#ignores any blank lines
if i == '':
continue
else:
fp.writelines([i])
fp.writelines('\n')
fp.close()
The problem I am having is that when read from the file later it includes the \n, so instead of python reading:
blablabla
it reads:
blablabla\n
How can I make it not read the \n? Or do I need to use something like re.split() to remove the \n prior to reading?
This seems like something really simple I am overlooking.
You can use rstrip.
i = i.rstrip('\n')
Related
I am still learning python and have a question about the function readlines() The following is a part of my script:
f = open("demofile.txt", "r")
text = "".join(f.readlines())
print(text)
demofile.txt contains:
This is the first line
This is the second line
This is the third line
Now I want to add a single word to this so I get:
This is the first line
This is the second line
This is the third line
Example
I thought of something easy way of doing it:
f = open("demofile.txt", "r")
text = "".join(f.readlines())."Example"
print(text)
But that doesn't work (of course) I googled and looked around here but didn't really have the good keywords to search for this issue. Hopefully someone can point me in the right direction.
.readlines() returns list you can append() to it:
with open("demofile.txt") as txt:
lines = txt.readlines()
lines.append("Example")
text = "".join(lines)
print(text)
or you can unpack the file object txt, since its an iterator to a new list with the word you wanted to add:
with open("demofile.txt") as txt:
text = "".join([*txt, "Example"])
print(text)
Firstly, the open function in python opens a file in read mode by default. Thus, you do not need to specify the mode r when opening the file. Secondly, you should always close a file after you are done with it. A with statement in python handles this for you. Moreover, instead of using . to add Example onto the end of the string, you should use the concatenation operator in python to add a newline character, \n, and the string, Example.
with open("demofile.txt") as f:
text = "".join(f.readlines()) + "\nExample"
print(text)
This should help you. While dealing with files. It is always recommended to use with open('filename','r') as f instead of f=open('filename','r'). Using ContextManager during file open is the idea that this file will be open in any case whether everything is ok or any exception is raised. And you don't need to explicitly close the file i.e f.close().
end_text='Example'
with open('test.txt','r') as f:
text=''.join(f.readlines())+'\n'+end_text
print(text)
I am trying to read the text within a .m file in Python and Python keeps reading a single character within the .m file as a line when I use file.readline(). I've also had issues with trying to remove certain parts of the line before adding it to a list.
I've tried adjusting where the readline is on for loops that I have set up since I have to read through multiple files in this program. No matter where I put it, the string always comes out separated by character. I'm new to Python so I'm trying my best to learn what to do.
# Example of what I did
with open('MyFile.m') as f:
for line in f:
text = f.readline()
if text.startswith('%'):
continue
else:
my_string = text.strip("=")
my_list.append(my_string)
This has only partially worked as it will still return parts of lines that I do not want and when trying to format the output by putting spaces between new lines it output like so:
Expected: "The String"
What happened: "T h e S t r i n g"
Without your input file I've had to make some guesses here
Input file:
%
The
%
String
%
Solution:
my_list = []
with open('MyFile.m') as f:
for line in f:
if not line.startswith('%'):
my_list.append(line.strip("=").strip())
print(' '.join(my_list))
The readLine() call was unnecessary as the for loop already gets you the line. The empty if was negated to only catch the part that you cared about. Without your actual input file I can't help with the '=' part. If you have any clarifications I'd be glad to help further.
As suggested by Xander, you shouldn't call readline since the for line in f does that for you.
my_list = []
with open('MyFile.m') as f:
for line in f:
line = line.strip() # lose the \n if you want to
if line.startswith('%'):
continue
else:
my_string = line.strip("=")
my_list.append(my_string)
EDIT: See bottom of post for the entire code
I am new to this forum and I have an issue that I would be grateful for any help solving.
Situation and goal:
- I have a list of strings. Each string is one word, like this: ['WORD', 'LINKS', 'QUOTE' ...] and so on.
- I would like to write this list of words (strings) on separate lines in a new text file.
- One would think the way to do this would be by appending the '\n' to every item in the list, but when I do that, I get a blank line between every list item. WHY?
Please have a look at this simple function:
def write_new_file(input_list):
with open('TEKST\\TEKST_ny.txt', mode='wt') as output_file:
for linje in input_list:
output_file.write(linje + '\n')
This produces a file that looks like this:
WORD
LINKS
QUOTE
If I remove the '\n', then the file looks like this:
WORDLINKSQUOTE
Instead, the file should look like this:
WORD
LINKS
QUOTE
I am obviously doing something wrong, but after a lot of experimenting and reading around the web, I can't seem to get it right.
Any help would be deeply appreciated, thank you!
Response to link to thread about write() vs. writelines():
Writelines() doesn't fix this by itself, it produces the same result as write() without the '\n'. Unless I add a newline to every list item before passing it to the writelines(). But then we're back at the first option and the blank lines...
I tried to use one of the answers in the linked thread, using '\n'.join() and then write(), but I still get the blank lines.
It comes down to this: For some reason, I get two newlines for every '\n', no matter how I use it. I am .strip()'ing the list items of newline characters to be sure, and without the nl everything is just one massive block of texts anyway.
On using another editor: I tried open the txt-file in windows notepad and in notepad++. Any reason why these programs wouldn't display it correctly?
EDIT: This is the entire code. Sorry for the Norwegian naming. The purpose of the program is to read and clean up a text file and return the words first as a list and ultimately as a new file with each word on a new line. The text file is a list of Scrabble-words, so it's rather big (9 mb or something). PS: I don't advocate Scrabble-cheating, this is just a programming exercise :)
def renskriv(opprinnelig_ord):
nytt_ord = ''
for bokstav in opprinnelig_ord:
if bokstav.isupper() == True:
nytt_ord = nytt_ord + bokstav
return nytt_ord
def skriv_ny_fil(ny_liste):
with open('NSF\\NSF_ny.txt', 'w') as f:
for linje in ny_liste:
f.write(linje + '\n')
def behandle_kildefil():
innfil = open('NSF\\NSF_full.txt', 'r')
f = innfil.read()
kildeliste = f.split()
ny_liste = []
for item in kildeliste:
nytt_ord = renskriv(item)
nytt_ord = nytt_ord.strip('\n')
ny_liste.append(nytt_ord)
skriv_ny_fil(ny_liste)
innfil.close()
def main():
behandle_kildefil()
if __name__ == '__main__':
main()
I think there must be some '\n' among your lines, try to skip empty lines.
I suggest you this code.
def write_new_file(input_list):
with open('TEKST\\TEKST_ny.txt', 'w') as output_file:
for linje in input_list:
if not linje.startswith('\n'):
output_file.write(linje.strip() + '\n')
You've said in the comments that python is writing two carriage return ('\r') characters for each line feed ('\n') character you write. It's a bit bizaare that python is replacing each line feed with two carriage returns, but this is a feature of opening a file in text mode (normally the translation would be to something more useful). If instead you open your file in binary mode then this translation will not be done and the file should display as you wish in Notepad++. NB. Using binary mode may cause problems if you need characters outside the ASCII range -- ASCII is basically just latin letters (no accents), digits and a few symbols.
For python 2 try:
filename = "somefile.txt"
with open(filename, mode="wb") as outfile:
outfile.write("first line")
outfile.write("\n")
outfile.write("second line")
Python 3 will be a bit more tricky. For each string literal you wish you write you must prepend it with a b (for binary). For each string you don't have immediate access to, or don't wish to change to a binary string, then you must encode it using the encode() method on the string. eg.
filename = "somefile.txt"
with open(filename, mode="wb") as outfile:
outfile.write(b"first line")
outfile.write(b"\n")
some_text = "second line"
outfile.write(some_text.encode())
How to remove whitespaces in the beginning of every string in a file with python?
I have a file myfile.txt with the strings as shown below in it:
_ _ Amazon.inc
Arab emirates
_ Zynga
Anglo-Indian
Those underscores are spaces.
The code must be in a way that it must go through each and every line of a file and remove all those whitespaces, in the beginning of a line.
I've tried using lstrip but that's not working for multiple lines and readlines() too.
Using a for loop can make it better?
All you need to do is read the lines of the file one by one and remove the leading whitespace for each line. After that, you can join again the lines and you'll get back the original text without the whitespace:
with open('myfile.txt') as f:
line_lst = [line.lstrip() for line in f.readlines()]
lines = ''.join(line_lst)
print lines
Assuming that your input data is in infile.txt, and you want to write this file to output.txt, it is easiest to use a list comprehension:
inf = open("infile.txt")
stripped_lines = [l.lstrip() for l in inf.readlines()]
inf.close()
# write the new, stripped lines to a file
outf = open("output.txt", "w")
outf.write("".join(stripped_lines))
outf.close()
To read the lines from myfile.txt and write them to output.txt, use
with open("myfile.txt") as input:
with open("output.txt", "w") as output:
for line in input:
output.write(line.lstrip())
That will make sure that you close the files after you're done with them, and it'll make sure that you only keep a single line in memory at a time.
The above code works in Python 2.5 and later because of the with keyword. For Python 2.4 you can use
input = open("myfile.txt")
output = open("output.txt", "w")
for line in input:
output.write(line.lstrip())
if this is just a small script where the files will be closed automatically at the end. If this is part of a larger program, then you'll want to explicitly close the files like this:
input = open("myfile.txt")
try:
output = open("output.txt", "w")
try:
for line in input:
output.write(line.lstrip())
finally:
output.close()
finally:
input.close()
You say you already tried with lstrip and that it didn't work for multiple lines. The "trick" is to run lstrip on each individual line line I do above. You can try the code out online if you want.
I have a wordlist that contains returns to separate each new letter. Is there a way to programatically delete each of these returns using file I/O in Python?
Edit: I know how to manipulate strings to delete returns. I want to physically edit the file so that those returns are deleted.
I'm looking for something like this:
wfile = open("wordlist.txt", "r+")
for line in wfile:
if len(line) == 0:
# note, the following is not real... this is what I'm aiming to achieve.
wfile.delete(line)
>>> string = "testing\n"
>>> string
'testing\n'
>>> string = string[:-1]
>>> string
'testing'
This basically says "chop off the last thing in the string" The : is the "slice" operator. It would be a good idea to read up on how it works as it is very useful.
EDIT
I just read your updated question. I think I understand now. You have a file, like this:
aqua:test$ cat wordlist.txt
Testing
This
Wordlist
With
Returns
Between
Lines
and you want to get rid of the empty lines. Instead of modifying the file while you're reading from it, create a new file that you can write the non-empty lines from the old file into, like so:
# script
rf = open("wordlist.txt")
wf = open("newwordlist.txt","w")
for line in rf:
newline = line.rstrip('\r\n')
wf.write(newline)
wf.write('\n') # remove to leave out line breaks
rf.close()
wf.close()
You should get:
aqua:test$ cat newwordlist.txt
Testing
This
Wordlist
With
Returns
Between
Lines
If you want something like
TestingThisWordlistWithReturnsBetweenLines
just comment out
wf.write('\n')
You can use a string's rstrip method to remove the newline characters from a string.
>>> 'something\n'.rstrip('\r\n')
>>> 'something'
The most efficient is to not specify a strip value
'\nsomething\n'.split() will strip all special characters and whitespace from the string
simply use, it solves the issue.
string.strip("\r\n")
Remove empty lines in the file:
#!/usr/bin/env python
import fileinput
for line in fileinput.input("wordlist.txt", inplace=True):
if line != '\n':
print line,
The file is moved to a backup file and standard output is directed to the input file.
'whatever\r\r\r\r\r\r\r\r\n\n\n\n\n'.translate(None, '\r\n')
returns
'whatever'
This is also a possible solution
file1 = open('myfile.txt','r')
conv_file = open("numfile.txt","w")
temp = file1.read().splitlines()
for element in temp:
conv_file.write(element)
file1.close()
conv_file.close()