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Store the contents of text file in return variable and manipulate wherever required in python?

I have below function & I am trying to get/store the contents of text file in another temp file(removing unnecessary line) with appending special character.
But I also want the same content which is in temp text file with different special character next time but I am not able to do that.Below function is creating a temp file.To get desired output I need to create file every time with same function again which is not good way.Is there anything we can do without creating a temp/extra file and store the contents in return variable and append the special character whatever we want multiple times
import os
import re
def mainfest():
pathfile = "abc_12.txt"
with open(pathfile, 'r') as firstfile, open('tmp.txt', 'r') as s:
for line in firstfile:
if line.strip().startswith("-") or line.startswith("<"):
print"ignore")
elif re.search('\\S', line):
name = str(os.path.basename(line))
s.write("*" +fname)
def contents():
temppath = "temp.txt"
with open(temp path, 'r') as f:
lines = f.readlines()
lines+= lines
return lines
manifest()
value = contents()
file abc_12.txt
---ABC-123
nice/abc.py
xml/abc.py
<<NOP-123
bac\nice.py
abc.py
---CDEF-345
jkl.oy
abc.py
I want the contents of abc_12.txt file I can get in return something like that
abc.py
abc.py
nice.py
abc.py
jkl.oy
abc.py
and manipulate them wherever I want similar to below output
Output 1:
* abc.py
* abc.py
* nice.py
* abc.py
* jkl.oy
* abc.py
Output 2:
##abc.py
##abc.py
##nice.py
##abc.py
##jkl.oy
##abc.py

Maybe first you should read file, search names and keep on list
def read_data():
results = []
with open("abc_12.txt") as infile:
for line in infile:
if line.strip().startswith(("-", "<")): # `startswith`/`endswith` can use tuple
print("ignore:", line)
elif re.search('\\S', line):
name = os.path.basename(line)
results.append(name)
return results
And later you can use this list to create temp file or other file
data = read_data()
with open('temp.txt', 'w') as outfile:
for line in data:
outfile.write(f'* {line}')
#print(f'* {line}', end='')
with open('other.txt', 'w') as outfile:
for line in data:
outfile.write(f'##{line}')
#print(f'##{line}', end='')
EDIT:
Minimal working code.
I used io.StringIO only to simulate file in memory - so everyone can simply copy and test it.
import os
import re
import io
text = r'''---ABC-123
nice/abc.py
xml/abc.py
<<NOP-123
bac\nice.py
abc.py
---CDEF-345
jkl.oy
abc.py
'''
def read_data():
results = []
with io.StringIO(text) as infile:
#with open("abc_12.txt") as infile:
for line in infile:
line = line.strip()
if line:
if line.startswith(("-", "<")): # `startswith`/`endswith` can use tuple
print("ignore:", line)
else:
name = os.path.basename(line)
results.append(name)
return results
data = read_data()
with open('temp.txt', 'w') as outfile:
for line in data:
outfile.write(f'* {line}\n')
print(f'* {line}')
with open('other.txt', 'w') as outfile:
for line in data:
outfile.write(f'##{line}\n')
print(f'##{line}')
EDIT:
If you don't want to save in file then you still need for-loop to create string
data = read_data()
string_1 = ''
for line in data:
string_1 += f'* {line}\n'
string_2 = ''
for line in data:
string_2 += f'##{line}\n'
or to create new list (and eventually string)
data = read_data()
list_1 = []
for line in data:
list_1.append(f'* {line}')
list_2 = []
for line in data:
list_2.append(f'##{line}')
string_1 = "\n".join(list_1)
string_2 = "\n".join(list_2)

How to edit specific line for all text files in a folder by python?

Here below is my code about how to edit text file.
Since python can't just edit a line and save it at the same time,
I save the previous text file's content into a list first then write it out.
For example,if there are two text files called sample1.txt and sample2.txt in the same folder.
Sample1.txt
A for apple.
Second line.
Third line.
Sample2.txt
First line.
An apple a day.
Third line.
Execute python
import glob
import os
#search all text files which are in the same folder with python script
path = os.path.dirname(os.path.abspath(__file__))
txtlist = glob.glob(path + '\*.txt')
for file in txtlist:
fp1 = open(file, 'r+')
strings = [] #create a list to store the content
for line in fp1:
if 'apple' in line:
strings.append('banana\n') #change the content and store into list
else:
strings.append(line) #store the contents did not be changed
fp2 = open (file, 'w+') # rewrite the original text files
for line in strings:
fp2.write(line)
fp1.close()
fp2.close()
Sample1.txt
banana
Second line.
Third line.
Sample2.txt
First line.
banana
Third line.
That's how I edit specific line for text file.
My question is : Is there any method can do the same thing?
Like using the other functions or using the other data type rather than list.
Thank you everyone.

Simplify it to this:
with open(fname) as f:
content = f.readlines()
content = ['banana' if line.find('apple') != -1 else line for line in content]
and then write value of content to file back.

Instead of putting all the lines in a list and writing it, you can read it into memory, replace, and write it using same file.
def replace_word(filename):
with open(filename, 'r') as file:
data = file.read()
data = data.replace('word1', 'word2')
with open(filename, 'w') as file:
file.write(data)
Then you can loop through all of your files and apply this function

The built-in fileinput module makes this quite simple:
import fileinput
import glob
with fileinput.input(files=glob.glob('*.txt'), inplace=True) as files:
for line in files:
if 'apple' in line:
print('banana')
else:
print(line, end='')
fileinput redirects print into the active file.

import glob
import os
def replace_line(file_path, replace_table: dict) -> None:
list_lines = []
need_rewrite = False
with open(file_path, 'r') as f:
for line in f:
flag_rewrite = False
for key, new_val in replace_table.items():
if key in line:
list_lines.append(new_val+'\n')
flag_rewrite = True
need_rewrite = True
break # only replace first find the words.
if not flag_rewrite:
list_lines.append(line)
if not need_rewrite:
return
with open(file_path, 'w') as f:
[f.write(line) for line in list_lines]
if __name__ == '__main__':
work_dir = os.path.dirname(os.path.abspath(__file__))
txt_list = glob.glob(work_dir + '/*.txt')
replace_dict = dict(apple='banana', orange='grape')
for txt_path in txt_list:
replace_line(txt_path, replace_dict)

Remove the last empty line from each text file

I have many text files, and each of them has a empty line at the end. My scripts did not seem to remove them. Can anyone help please?
# python 2.7
import os
import sys
import re
filedir = 'F:/WF/'
dir = os.listdir(filedir)
for filename in dir:
if 'ABC' in filename:
filepath = os.path.join(filedir,filename)
all_file = open(filepath,'r')
lines = all_file.readlines()
output = 'F:/WF/new/' + filename
# Read in each row and parse out components
for line in lines:
# Weed out blank lines
line = filter(lambda x: not x.isspace(), lines)
# Write to the new directory
f = open(output,'w')
f.writelines(line)
f.close()

You can use Python's rstrip() function to do this as follows:
filename = "test.txt"
with open(filename) as f_input:
data = f_input.read().rstrip('\n')
with open(filename, 'w') as f_output:
f_output.write(data)
This will remove all empty lines from the end of the file. It will not change the file if there are no empty lines.

you can remove last empty line by using:
with open(filepath, 'r') as f:
data = f.read()
with open(output, 'w') as w:
w.write(data[:-1])

You can try this without using the re module:
filedir = 'F:/WF/'
dir = os.listdir(filedir)
for filename in dir:
if 'ABC' in filename:
filepath = os.path.join(filedir,filename)
f = open(filepath).readlines()
new_file = open(filepath, 'w')
new_file.write('')
for i in f[:-1]:
new_file.write(i)
new_file.close()
For each filepath, the code opens the file, reads in its contents line by line, then writes over the file, and lastly writes the contents of f to the file, except for the last element in f, which is the empty line.

You can remove the last blank line by the following command. This worked for me:
file = open(file_path_src,'r')
lines = file.read()
with open(file_path_dst,'w') as f:
for indx, line in enumerate(lines):
f.write(line)
if indx != len(lines) - 1:
f.write('\n')

i think this should work fine
new_file.write(f[:-1])

Python check if value in csv file

i got list of URLs, for example:
urls_list = [
"http://yandex.ru",
"http://google.ru",
"http://rambler.ru",
"http://google.ru",
"http://gmail.ru",
"http://mail.ru"
]
I need to open the csv file, check if each value from list in file - skip to next value, else (if value not in a list) add this value in list.
Result: 1st run - add all lines (if file is empty), 2nd run - doing nothing, because all elements in already in file.
A wrote code, but it's work completely incorrect:
import csv
urls_list = [
"http://yandex.ru",
"http://google.ru",
"http://rambler.ru",
"http://google.ru",
"http://gmail.ru",
"http://mail.ru"
]
with open('urls_list.csv', 'r') as fp:
for row in fp:
for url in urls_list:
if url in row:
print "YEY!"
with open('urls_list.csv', 'a+') as fp:
wr = csv.writer(fp, dialect='excel')
wr.writerow([url])

Read the file into a variable-
with open('urls_list.csv', 'r') as fp:
s = fp.read()
Check to see if each list item is in the file, if not save it
missing = []
for url in urls_list:
if url not in s:
missing.append(url + '\n')
Write the missing url's to the file
if missing:
with open('urls_list.csv', 'a+') as fp:
fp.writelines(missing)

Considering your file has only one column, the csv module might be an overkill.
Here's a version that first reads all the lines from the file and reopens the file to write urls that are not already in the file:
lines = open('urls_list.csv', 'r').read()
with open('urls_list.csv', 'a+') as fp:
for url in urls_list:
if url in lines:
print "YEY!"
else:
fp.write(url+'\n')

Want to read multiple csv file one by one and filepaths are stored in a text file using python

here is my code for readinng individual cell of one csv file. but want to read multiple csv file one by one from .txt file where csv file paths are located.
import csv
ifile = open ("C:\Users\BKA4ABT\Desktop\Test_Specification\RDBI.csv", "rb")
data = list(csv.reader(ifile, delimiter = ';'))
REQ = []
RES = []
n = len(data)
for i in range(n):
x = data[i][1]
y = data[i][2]
REQ.append (x)
RES.append (y)
i += 1
for j in range(2,n):
try:
if REQ[j] != '' and RES[j]!= '': # ignore blank cell
print REQ[j], ' ', RES[j]
except:
pass
j += 1
And csv file paths are stored in a .txt file like
C:\Desktop\Test_Specification\RDBI.csv
C:\Desktop\Test_Specification\ECUreset.csv
C:\Desktop\Test_Specification\RDTC.csv
and so on..

You can read stuff stored in files into variables. And you can use variables with strings in them anywhere you can use a literal string. So...
with open('mytxtfile.txt', 'r') as txt_file:
for line in txt_file:
file_name = line.strip() # or was it trim()? I keep mixing them up
ifile = open(file_name, 'rb')
# ... the rest of your code goes here
Maybe we can fix this up a little...
import csv
with open('mytxtfile.txt', 'r') as txt_file:
for line in txt_file:
file_name = line.strip()
csv_file = csv.reader(open(file_name, 'rb', delimiter=';'))
for record in csv_file[1:]: # skip header row
req = record[1]
res = record[2]
if len(req + res):
print req, ' ', res

you just need to add a while which will read your file containing your list of files & paths upon your first open statement, for example
from __future__ import with_statement
with open("myfile_which_contains_file_path.txt") as f:
for line in f:
ifile = open(line, 'rb')
# here the rest of your code

You need to use a raw string string your path contains \
import csv
file_list = r"C:\Users\BKA4ABT\Desktop\Test_Specification\RDBI.csv"
with open(file_list) as f:
for line in f:
with open(line.strip(), 'rb') as the_file:
reader = csv.reader(the_file, delimiter=';')
for row in reader:
req,res = row[1:3]
if req and res:
print('{0} {1}'.format(req, res))