I'm trying to remove one line which matches a variable. But instead it is wiping the file clean.
a_file = open("./Variables/TxtFile.txt", "r")
lines = a_file.readlines()
a_file.close()
new_file = open("./Variables/TxtFile.txt", "w")
for line in lines:
if line.strip("\n") == VariableStore:
new_file.write(line)
new_file.close()
The goal would be to remove the line that matches VariableStore rather than wiping the entire text file
In regard to my comment to your original post.
You only write to the file if you match the line you want to remove and then also close the file.
This seems not to be what you want.
You might want to change the if condition to be executed in cases that do not match your line you want to remove, i.e., to if not line.strip("\n") == VariableStore: and close the file after your loop, i.e., on the same level as your for loop.
Try the following, which incorporates these suggestions:
a_file = open("./Variables/TxtFile.txt", "r")
lines = a_file.readlines()
a_file.close()
new_file = open("./Variables/TxtFile.txt", "w")
for line in lines:
if not line.strip("\n") == VariableStore:
new_file.write(line)
new_file.close()
If your aim is to filter out the line matching VariableStore, do this:
with open("./Variables/TxtFile.txt", "r") as a_file:
lines = a_file.readlines()
with open("./Variables/TxtFile.txt", "w") as new_file:
for line in lines:
if line.strip("\n") != VariableStore:
continue # Skip the VariableStore line
new_file.write(line) # Write other lines
When you use with statements, you don't need to manually close the file.
You just need to close the file later on, when you are done parsing all the lines.
Also, you need to write the lines that don't match, not the one's that do.
Note the changes below:
# Read file
a_file = open("./Variables/TxtFile.txt", "r")
lines = a_file.readlines()
a_file.close()
# Write file
new_file = open("./Variables/TxtFile.txt", "w")
for line in lines:
if line.strip("\n") == VariableStore:
# Don't write this line
pass
else:
new_file.write(line)
new_file.close()
Let us assume that your text file TxtFile.txt contains this text
Hello
World
I'm
Python
Developer
And you have a variable var contains the string World which we want to remove from the text file.
Here is a python code does the job in few lines
var='World' # a string to remove
with open("TxtFile.txt","r+") as f:
lines = f.readlines()
lines = [line for line in lines if line.strip()!=var]
f.seek(0)
f.writelines(lines)
f.truncate()
The text file after running this code..
Hello
I'm
Python
Developer
The problem is that you're opening the file with write mode instead of append mode. Replace
new_file = open("./Variables/TxtFile.txt", "w")
with
new_file = open("./Variables/TxtFile.txt", "a")
and you'll append the data instead of overwriting it.
Also, it's generally recommended to open files using the 'with' statement, since that automatically closes the file for you.
with open("./Variables/TxtFile.txt", "a") as text_file:
...
Related
I've scraped some comments from a webpage using selenium and saved them to a text file. Now I would like to perform multiple edits to the text file and save it again. I've tried to group the following into one smooth flow but I'm fairly new to python so I just couldn't get it right. Examples of what happened to me at the bottom. The only way I could get it to work is to open and close the file over and over.
These are the action I want to perform in the order the need to:
with open('results.txt', 'r') as f:
lines = f.readlines()
with open("results.txt", "w") as f:
for line in lines:
f.write(line.replace("a sample text line", ' '))
with open('results.txt', 'r') as f:
lines = f.readlines()
with open("results.txt", "w") as f:
pattern = r'\d in \d example text'
for line in lines:
f.write(re.sub(pattern, "", line))
with open('results.txt', 'r') as f:
lines = f.readlines()
with open('results.txt','w') as file:
for line in lines:
if not line.isspace():
file.write(line)
with open('results.txt', 'r') as f:
lines = f.readlines()
with open("results.txt", "w") as f:
for line in lines:
f.write(line.replace(" ", '-'))
I've tried to loop them into one but I get doubled lines, words, or extra spaces.
Any help is appreciated, thank you.
If you want to do these in one smooth pass, you better open another file to write the desired results i.e.
import re
pattern = r"\d in \d example text"
# Open your results file for reading and another one for writing
with open("results.txt", "r") as fh_in, open("output.txt", "w") as fh_out:
for line in fh_in:
# Process the line
line = line.replace("a sample text line", " ")
line = re.sub(pattern, "", line)
if line.isspace():
continue
line = line.replace(" ", "-")
# Write out
fh_out.write(line)
We process each line in order you described and the resultant line goes to output file.
I am trying to do what for many will be a very straight forward thing but for me is just infuriatingly difficult.
I am trying search for a line in a file that contains certain words or phrases and modify that line...that's it.
I have been through the forum and suggested similar questions and have found many hints but none do just quite what I want or are beyond my current ability to grasp.
This is the test file:
# 1st_word 2nd_word
# 3rd_word 4th_word
And this is my script so far:
############################################################
file = 'C:\lpthw\\text'
f1 = open(file, "r+")
f2 = open(file, "r+")
############################################################
def wrline():
lines = f1.readlines()
for line in lines:
if "1st_word" in line and "2nd_word" in line:
#f2.write(line.replace('#\t', '\t'))
f2.write((line.replace('#\t', '\t')).rstrip())
f1.seek(0)
wrline()
My problem is that the below inserts a \n after the line every time and adds a blank line to the file.
f2.write(line.replace('#\t', '\t'))
The file becomes:
1st_word 2nd_word
# 3rd_word 4th_word
An extra blank line between the lines of text.
If I use the following:
f2.write((line.replace('#\t', '\t')).rstrip())
I get this:
1st_word 2nd_wordd
# 3rd_word 4th_word
No new blank line inserted but and extra "d" at the end instead.
What am I doing wrong?
Thanks
Your blank line is coming from the original blank line in the file. Writing a line with nothing in it writes a newline to the file. Instead of not putting anything into the written line, you have to completely skip the iteration, so it does not write that newline. Here's what I suggest:
def wrline():
lines = open('file.txt', 'r').readlines()
f2 = open('file.txt', 'w')
for line in lines:
if '1st_word' in line and '2nd_word' in line:
f2.write((line.replace('# ', ' ')).rstrip('\n'))
else:
if line != '\n':
f2.write(line)
f2.close()
I would keep read and write operations separate.
#read
with open(file, 'r') as f:
lines = f.readlines()
#parse, change and write back
with open(file, 'w') as f:
for line in lines:
if line.startswith('#\t'):
line = line[1:]
f.write(line)
You have not closed the files and there is no need for the \t
Also get rid of the rstrip()
Read in the file, replace the data and write it back.. open and close each time.
fn = 'example.txt'
new_data = []
# Read in the file
with open(fn, 'r+') as file:
filedata = file.readlines()
# Replace the target string
for line in filedata:
if "1st_word" in line and "2nd_word" in line:
line = line.replace('#', '')
new_data.append(line)
# Write the file out again
with open(fn, 'w+') as file:
for line in new_data:
file.write(line)
I'm trying to open a text file that will allow me to read multiple lines and have them become capitalised
inputFileName = input("Input file name: ")
infile = open(inputFileName, "w+")
infile = open(inputFileName, "a")
infile = open(inputFileName, "r+")
line = infile.readline()
while line != "" :
line = infile.readline()
line = line.upper()
outfile.write(line)
print(line)
infile.close()
When opening it would not give the context of the file itself, even though what I wrote should work
as the comments have begun to mention, and in reference to your final statement, this code absolutely should not work, for multiple reasons.
1) you open the file three times, for no apparent reason.
2) outfile isn't declared, doesn't do anything.
3) when you open a file with w it clears the contents of afformentioned file.
firstly fix these issues.
you understand the fundementals, your upper function is fine etc etc.
this is what you must do.
1) dont open the same file 3 times for no reason
2) define outfile
3) use a instead of w so you append rather then delete and write
This will work.
f_name = input("Input file name: ")
with open(f_name, "r+") as f:
lines = f.read().splitlines() # get string, split lines
lines = [l.capitalize() for l in lines] # capitalize each line
f.seek(0) # move the cursor to the beginning
f.write('\n'.join(lines)) # join the lines and write to the same file
I have a text file that looks like this
Big:house
small:door
Big:car
Small:chair
Big:plane
How to I remove the lines that contain the word "big" so it may look like this, I dont want to create a new file all together though
small:door
small:chair
Here was my attempt
with open('QWAS.txt','r') as oldfile:
for line in oldfile:
if bad_words in line:
newfile.write(line)
This is what we can do:
Read data to string (remove rows that start with 'big')
Go to the start of file (seek)
Write the string
Truncate (remove overflow)
And now to the code, open it in read and write mode:
with open('QWAS.txt','r+') as f:
data = ''.join([i for i in f if not i.lower().startswith('big')]) #1
f.seek(0) #2
f.write(data) #3
f.truncate() #4
Try this:
newfile = r'output.txt'
oldfile = r'input.txt'
with open(newfile, 'w') as outfile, open(oldfile, 'r') as infile:
for line in infile:
if if line[:5].lower() == 'small':
outfile.write(line)
#output
small:door
Small:chair
Of course, this assumes you want to eliminate rows where small or Small is to the left of the colon. Additionally, you will have a new file output, as I don't think you really want to update your input file.
You can try using regular expressions
import re
oldfile = open('QWAS.txt','r')
newfile = open('newfile.txt','w')
for line in oldfile:
if re.search('[Ss]mall',line):
newfile.write(line)
oldfile.close()
newfile.close()
Which gives the output file "newfile.txt"
small:door
Small:chair
If you just take every line that doesn't have small and write it to a new file "newfile2.txt"
import re
oldfile = open('QWAS.txt','r')
newfile = open('newfile.txt','w')
newfile2 = open('newfile2.txt','w')
for line in oldfile:
if re.search('[Ss]mall',line):
newfile.write(line)
else:
newfile2.write(line)
oldfile.close()
newfile.close()
newfile2.close()
The global variable originalInfo contains
Joe;Bloggs;j.bloggs#anemail.com;0715491874;1
I have written a function to delete that line in a text file containing more information of this type. It works, but it is really clunky and inelegant.
f = open("input.txt",'r') # Input file
t = open("output.txt", 'w') #Temp output file
for line in f:
if line != originalInfo:
t.write(line)
f.close()
t.close()
os.remove("input.txt")
os.rename('output.txt', 'input.txt')
Is there a more efficient way of doing this? Thanks
You solution nearly works, but you need to take care of the trailing newline. This is bit shorter version, doing what you intend:
import shutil
with open("input.txt",'r') as fin, open("output.txt", 'w') as fout:
for line in fin:
if line.strip() != originalInfo:
fout.write(line)
shutil.move('output.txt', 'input.txt')
The strip() is a bit extra effort but would strip away extra white space.
Alternatively, you could do:
originalInfo += '\n'
and later in the loop:
if line != originalInfo:
You can open the file, read it by readlines(), close it and open it to write again. With this way you don't have to create an output file:
with open('input.txt') as file:
lines = file.readlines
with open('input.txt') as file:
for line in lines:
if line != originalInfo:
file.write(line)
But if you want to have an output:
with open('input.txt') as input:
with open('output.txt', 'w') as output:
for line in input:
if line != originalInfo:
output.write(line)