I have a text file like this:-
V1xx AB1
V2xx AC34
V3xx AB1
Can we add ; at each end of line through python script?
V1xx AB1;
V2xx AC34;
V3xx AB1;
Here's what you can try. I have overwritten the same file though.
You can try creating a new one(I leave it to you) - You'll need to modify your with statement a little : -
lines = ""
with open('D:\File.txt') as file:
for line in file:
lines += line.strip() + ";\n"
file = open('D:\File.txt', "w+")
file.writelines(lines)
file.flush()
UPDATE: - For in-place modification of file, you can use fileinput module: -
import fileinput
for line in fileinput.input('D:\File.txt', inplace = True):
print line.strip() + ";"
input_file_name = 'input.txt'
output_file_name = 'output.txt'
with open(input_file_name, 'rt') as input, open(output_file_name, 'wt') as output:
for line in input:
output.write(line[:-1]+';\n')
#Open the original file, and create a blank file in write mode
File = open("D:\myfilepath\myfile.txt")
FileCopy = open("D:\myfilepath\myfile_Copy.txt","w")
#For each line in the file, remove the end line character,
#insert a semicolon, and then add a new end line character.
#copy these lines into the blank file
for line in File:
CleanLine=line.strip("\n")
FileCopy.write(CleanLine+";\n")
FileCopy.close()
File.close()
#Replace the original file with the copied file
File = open("D:\myfilepath\myfile.txt","w")
FileCopy = open("D:\myfilepath\myfile_Copy.txt")
for line in FileCopy:
File.write(line)
FileCopy.close()
File.close()
Notes: I have left the "copy file" in there as a back up. You can manually delete it or use os.remove() (if you do that don't forget to import the os module)
Related
How to fetch the second line data from text file in Python.
I have a text file and in file there are some data in line by line_
Dog
Cat
Cow
How to fetch the second line which is “Cat” and store in a variable in python
var = # “Cat”
You should place the text file in the same directory with your Python code, which could be the following:
with open("animals.txt", "r") as f:
animals = [line.strip() for line in f]
second_line = animals[1]
Now, the variable "second_line" contains the data you want.
You can open a file, then read line by line while counting the line number as follows:
if __name__ == '__main__':
input_path = "data/animals.txt"
var = None
with open(input_path, "r") as fin:
n_lines = 0
for line in fin:
n_lines += 1
if 2 == n_lines:
var = line.strip()
break
print(var)
Result:
Cat
If the file is big, you may avoid reading all file and use readline to read one line twice:
with open ('file.txt') as file:
line = file.readline()
line = file.readline()
print(line)
...or check 'seek' method to start reading at specific character index.
I am working on NLP project and have extracted the text from pdf using PyPDF2. Further, I removed the blank lines. Now, my output is being shown on the console but I want to populate the text file with the same data which is stored in my variable (file).
Below is the code which is removing the blank lines from a text file.
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file=line
print(file)
Output on Console:
Eclipse,
Visual Studio 2012,
Arduino IDE,
Java
,
HTML,
CSS
2013
Excel
.
Now, I want the same data in my (resume1.txt) text file. I have used three methods but all these methods print a single dot in my resume1.txt file. If I see at the end of the text file then there is a dot which is being printed.
Method 1:
with open("resume1.txt", "w") as out_file:
out_file.write(file)
Method 2:
print(file, file=open("resume1.txt", 'w'))
Method 3:
pathlib.Path('resume1.txt').write_text(file)
Could you please be kind to assist me in populating the text file. Thank you for your cooperation.
First of all, note that you are writing to the same file losing the old data, I don't know if you want to do that. Other than that, every time you write using those methods, you are overwriting the data you previously wrote to the output file. So, if you want to use these methods, you must write just 1 time (write all the data).
SOLUTIONS
Using method 1:
to_file = []
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file = line
print(file)
to_file.append(file)
to_save = '\n'.join(to_file)
with open("resume1.txt", "w") as out_file:
out_file.write(to_save)
Using method 2:
to_file = []
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file = line
print(file)
to_file.append(file)
to_save = '\n'.join(to_file)
print(to_save, file=open("resume1.txt", 'w'))
Using method 3:
import pathlib
to_file = []
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file = line
print(file)
to_file.append(file)
to_save = '\n'.join(to_file)
pathlib.Path('resume1.txt').write_text(to_save)
In these 3 methods, I have used to_save = '\n'.join(to_file) because I'm assuming you want to separate each line of other with an EOL, but if I'm wrong, you can just use ''.join(to_file) if you want not space, or ' '.join(to_file) if you want all the lines in a single one.
Other method
You can do this by using other file, let's say 'output.txt'.
out_file = open('output.txt', 'w')
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file = line
print(file)
out_file.write(file)
out_file.write('\n') # EOL
out_file.close()
Also, you can do this (I prefer this):
with open('output.txt', 'w') as out_file:
for line in open('resume1.txt'):
line = line.rstrip()
if line != '':
file = line
print(file)
out_file.write(file)
out_file.write('\n') # EOL
First post on stack, so excuse the format
new_line = ""
for line in open('resume1.txt', "r"):
for char in line:
if char != " ":
new_line += char
print(new_line)
with open('resume1.txt', "w") as f:
f.write(new_line)
I have a text file which contains the following paragraph:
The above with statement will automatically close the file after the nested block of code. The above with statement will automatically close the file after the nested block of code. The above with statement will automatically close the file after the nested block of code.
The above with statement will automatically close the file after the nested block of code without.
Now, I would like to modify the file by separating the individual lines for the paragraph, and save it in the same text file as the following:
The above with statement will automatically close the file after the nested block of code.
The above with statement will automatically close the file after the nested block of code.
The above with statement will automatically close the file after the nested block of code.
The above with statement will automatically close the file after the nested block of code without.
I was able to do it, but it was bit complicated. My code is as follows:
try-1
file = open("file_path")
content = file.read()
file.close()
file = open("file_path", 'w')
a = content.replace('. ', '.\n')
file.write(a)
file.close()
try-2
file = open("file_path")
contents = file.readlines()
file.close()
b = []
for line in contents:
if not line.strip():
continue
else:
b.append(line)
b = "".join(b)
file = open("file_path", 'w')
file.write(b)
file.close()
I opened the file twice to read and twice to write, is there any better way to separate the line from a paragraph from a text file, and writing it to the same text file?
You can do:
with open('filepath', 'r') as contents, open('filepath', 'w') as file:
contents = contents.read()
lines = contents.split('. ')
for index, line in enumerate(lines):
if index != len(lines) - 1:
file.write(line + '.\n')
else:
file.write(line + '.')
You can use seek method of files to jump in current file:
f.seek(offset, from_what)
And if you want to use file for write and read use option r+:
file = open("file_path", 'r+')
You also can skip step with readlines and use file iteration. Code should be:
file = open("file_path", "r+")
content = file.read()
a = content.replace('. ', '.\n')
file.seek(0)
file.write(a)
file.seek(0)
b = []
for line in file:
if not line.strip():
continue
else:
b.append(line)
b = "".join(b)
file.seek(0)
file.write(b)
file.close()
I'm trying to add specific lines to a specific area in my file.
I am using this:
new_file = open("file.txt", "r+")
for line in new_file:
if line == "; Include below":
line = line + "\nIncluded text"
new_file.write(line)
else:
new_file.write(line)
But for some reason the content of my file.txt is duplicating.
Edit: If my file looks like:
blablablablablablabal
balablablabalablablbla
include below
blablablablablabalablab
ablablablabalbalablaba
I want make it look like:
blablablablablablabal
balablablabalablablbla
include below
included text
blablablablablabalablab
ablablablabalbalablaba
You cannot safely write to a file while reading, it is better to read the file into memory, update it, and rewrite it to file.
with open("file.txt", "r") as in_file:
buf = in_file.readlines()
with open("file.txt", "w") as out_file:
for line in buf:
if line == "; Include this text\n":
line = line + "Include below\n"
out_file.write(line)
This is what I did.
def find_append_to_file(filename, find, insert):
"""Find and append text in a file."""
with open(filename, 'r+') as file:
lines = file.read()
index = repr(lines).find(find) - 1
if index < 0:
raise ValueError("The text was not found in the file!")
len_found = len(find) - 1
old_lines = lines[index + len_found:]
file.seek(index)
file.write(insert)
file.write(old_lines)
# end find_append_to_file
Use sed:
$ sed '/^include below/aincluded text' < file.txt
Explanation:
/^include below/: matches every line that starts (^) with include below
a: appends a newline and the following text
includeed text: the text that a appends
Edit: Using Python:
for line in open("file.txt").readlines():
print(line, end="")
if line.startswith("include below"):
print("included text")
I am trying to replace text in a text file by reading each line, testing it, then writing if it needs to be updated. I DO NOT want to save as a new file, as my script already backs up the files first and operates on the backups.
Here is what I have so far... I get fpath from os.walk() and I guarantee that the pathmatch var returns correctly:
fpath = os.path.join(thisdir, filename)
with open(fpath, 'r+') as f:
for line in f.readlines():
if '<a href="' in line:
for test in filelist:
pathmatch = file_match(line, test)
if pathmatch is not None:
repstring = filelist[test] + pathmatch
print 'old line:', line
line = line.replace(test, repstring)
print 'new line:', line
f.write(line)
But what ends up happening is that I only get a few lines (updated correctly, mind you, but repeated from earlier in the file) corrected. I think this is a scoping issue, afaict.
*Also: I would like to know how to only replace the text upon the first instance of the match, for ex., I don't want to match the display text, only the underlying href.
First, you want to write the line whether it matches the pattern or not. Otherwise, you're writing out only the matched lines.
Second, between reading the lines and writing the results, you'll need to either truncate the file (can f.seek(0) then f.truncate()), or close the original and reopen. Picking the former, I'd end up with something like:
fpath = os.path.join(thisdir, filename)
with open(fpath, 'r+') as f:
lines = f.readlines()
f.seek(0)
f.truncate()
for line in lines:
if '<a href="' in line:
for test in filelist:
pathmatch = file_match(line, test)
if pathmatch is not None:
repstring = filelist[test] + pathmatch
line = line.replace(test, repstring)
f.write(line)
Open the file for read and copy all of the lines into memory. Close the file.
Apply your transformations on the lines in memory.
Open the file for write and write out all the lines of text in memory.
with open(filename, "r") as f:
lines = (line.rstrip() for line in f)
altered_lines = [some_func(line) if regex.match(line) else line for line in lines]
with open(filename, "w") as f:
f.write('\n'.join(altered_lines) + '\n')
A (relatively) safe way to replace a line in a file.
#!/usr/bin/python
# defensive programming style
# function to replace a line in a file
# and not destroy data in case of error
def replace_line(filepath, oldline, newline ):
"""
replace a line in a temporary file,
then copy it over into the
original file if everything goes well
"""
# quick parameter checks
assert os.exists(filepath) # !
assert ( oldline and str(oldline) ) # is not empty and is a string
assert ( newline and str(newline) )
replaced = False
written = False
try:
with open(filepath, 'r+') as f: # open for read/write -- alias to f
lines = f.readlines() # get all lines in file
if oldline not in lines:
pass # line not found in file, do nothing
else:
tmpfile = NamedTemporaryFile(delete=True) # temp file opened for writing
for line in lines: # process each line
if line == oldline: # find the line we want
tmpfile.write(newline) # replace it
replaced = True
else:
tmpfile.write(oldline) # write old line unchanged
if replaced: # overwrite the original file
f.seek(0) # beginning of file
f.truncate() # empties out original file
for tmplines in tmpfile:
f.write(tmplines) # writes each line to original file
written = True
tmpfile.close() # tmpfile auto deleted
f.close() # we opened it , we close it
except IOError, ioe: # if something bad happened.
printf ("ERROR" , ioe)
f.close()
return False
return replaced and written # replacement happened with no errors = True
(note: this replaces entire lines only , and all of the lines that match in the file)