Develop Reference

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)

keep data in the file python

hi guys how are you I hope that well, I'm new using python and I'm doing a program but I dont know how to save the data permanently in a file. I only know how to create the file but i dont know how can i keep the data on the file eventhough the program be closed and when i open it back i be able to add more data and keep it in the file too.I have also tried several methods to upload the file on python but they didnt work for me. Can someone please help me?
This is my code:
file = open ('file.txt','w')
t = input ('name :')
p= input ('last name: ')
c = input ('nickname: ')
file.write('name :')
file.write(t)
file.write(' ')
file.write('last name: ')
file.write(p)
file.write('nickname: ')
file.write(c)
file.close()
with open('archivo.txt','w') as file:
data = load(file)
print(data)

Here is a demonstration of how file writing works, and the difference between w and a. The comments represent the text in the file that is written to the drive at each given point.
f1 = open('appending.txt', 'w')
f1.write('first string\n')
f1.close()
# first string
f2 = open('appending.txt', 'a')
f2.write('second string\n')
f2.close()
# first string
# second string
f3 = open('appending.txt', 'w')
f3.write('third string\n')
f3.close()
# third string

There are three type of File operation mode can happen on file like read, write and append.
Read Mode: In this you only able to read the file like
#content in file.txt "Hi I am Python Developer"
with open('file.txt', 'r') as f:
data = f.read()
print(data)
#output as : Hi I am Python Developer
Write Mode: In this you are able to write information into files, but it will always overwrite the content of the file like for example.
data = input('Enter string to insert into file:')
with open('file.txt', 'w') as f:
f.write(data)
with open('file.txt', 'r') as f:
data = f.read()
print('out_data:', data)
# Output : Enter string to insert into file: Hi, I am developer
# out_data: Hi, I am developer
When you open file for next time and do same write operation, it will overwrite whole information into file.
Append Mode: In this you will able to write into file but the contents is append into this files. Like for example:
data = input('Enter string to insert into file:')
with open('file.txt', 'a') as f:
f.write(data)
with open('file.txt', 'r') as f:
data = f.read()
print('out_data:', data)
# Output : Enter string to insert into file: Hi, I am developer
# out_data: Hi, I am developer
# Now perform same operation:
data = input('Enter string to insert into file:')
with open('file.txt', 'a') as f:
f.write(data)
with open('file.txt', 'r') as f:
data = f.read()
print('out_data:', data)
# Output : Enter string to insert into file: Hi, I am Python developer
# out_data: Hi, I am developer Hi, I am Python Developer

How to loop through a list of strings in Python

I'm a bit new to Python and I am trying to simplify my existing code.
Right now, I have the code repeated 5 times with different strings. I'd like to have the code one time and have it run through a list of strings.
Currently what I have:
def wiScanFormat():
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
MAC = data.replace("Address:", "\nAddress, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(MAC)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
SSID = data.replace("ESSID:", "\nESSID, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(SSID)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
FREQ = data.replace("Frequency:", "\nFrequency, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(FREQ)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
QUAL = data.replace("Quality", "\nQuality, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(QUAL)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
SIG = data.replace("Signal level", "\nSignal Level, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(SIG)
File.close()
What I'd like to have:
ORG = ['Address:', 'ESSID:'...etc]
NEW = ['\nAddress, ' , '\nESSID, ' , ... etc]
and run that through:
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
ID = data.replace("ORG", "NEW")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(ID)
File.close()
I've tried running exactly what I put up, but it does not seem to format it the way I need to.
The output from above looks like:
Cell 46 - Address: xx:xx:xx:xx:xx:xx ESSID:"MySSID" Frequency:2.412 GHz (Channel 1) Quality=47/100 Signal level=48/100 Quality=47/100 Signal level=48/100
But it is supposed to look like this (And it does when I run that same block over the strings separately):
xx:xx:xx:xx:xx:xx MySSID 5.18 GHz (Channel 36) 0.81 0.99
How should I go about looping this block of code through my list of strings?
There two strings that I would need for the find and replace, old and new, so they would have to work together. These lists will be the same size, obviously, and I need them to be in the correct order. Address with address, ESSID with ESSID, etc.
Thanks in advance!

Try something like this:
ORG = ['Address:', 'ESSID:'...etc]
NEW = ['\nAddress, ' , '\nESSID, ' , ... etc]
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
for org, new in zip(ORG, NEW):
data = data.replace(org, new)
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(data)
File.close()
(Note the way zip works: https://docs.python.org/2/library/functions.html#zip)

If I am reading your question right, you are opening the same file, making a small alteration, saving it, and then closing it again, five times. You could just open it once, make all the alterations, and then save it. For instance, like this:
filename = "/home/pi/gpsMaster/WiScan.txt"
with open(filename, 'r') as fin:
data = fin.read()
data = data.replace("Address:", "\nAddress, ")
data = data.replace("ESSID:", "\nESSID, ")
data = data.replace("Frequency:", "\nFrequency, ")
data = data.replace("Quality", "\nQuality, ")
data = data.replace("Signal level", "\nSignal Level, ")
with open(filename, 'w') as fout:
fout.write(data)
If you want to use lists (ORG and NEW) for your replacements, you could do this:
with open(filename, 'r') as fin:
data = fin.read()
for o,n in zip(ORG, NEW):
data = data.replace(o,n)
with open(filename, 'w') as fout:
fout.write(data)

Given your ORG and NEW, the simplest way to do this would be something like:
# Open once for both read and write; use with statement for guaranteed close at end of block
with open("/home/pi/gpsMaster/WiScan.txt", "r+") as f:
data = f.read() # Slurp file
f.seek(0) # Seek back to beginning of file
# Perform all replacements
for orig, repl in zip(ORG, NEW):
data = data.replace(orig, repl)
f.write(data) # Write new data over old
f.truncate() # If replacement shrunk file, truncate extra

You could just do this:
def wiScanFormat(path = "/home/pi/gpsMaster/WiScan.txt"):
# List of tuples with strings to find and strings to replace with
replacestr = [
("Address:", "\nAddress, "),
("ESSID:", "\nESSID, "),
("Frequency:", "\nFrequency, "),
("Quality", "\nQuality, "),
("Signal level", "\nSignal Level, ")
]
with open(path, "r") as file: # Open a file
data = file.read()
formated = data
for i in replacestr: # Loop over each element (tuple) in the list
formated = formated.replace(i[0], i[1]) # Replace the data
with open(path, "w") as file:
written = file.write(formated) # Write the data
return written

how to read the content of .txt file using python?

output_filename = r"C:\Users\guage\Output.txt"
RRA:
GREQ-299684_6j
GREQ-299684_6k
CZM:
V-GREQ-299684_6k
V-GREQ-299524_9
F_65624_1
R-GREQ-299680_5
DUN:
FB_71125_1
FR:
VQ-299659_18
VR-GREQ-299659_19
VEQ-299659_28
VR-GREQ-299659_31
VR-GREQ-299659_32
VEQ-299576_1
GED:
VEQ-299622_2
VR-GREQ-299618_13
VR-GREQ-299559_1
VR-GREQ-299524_14
FB_65624_1
VR-GREQ-299645_1
MNT:
FB_71125_1
FB_71125_2
VR-534_4
The above is the content of the the .txt file. how can I read it separately the content of it. for example -
RRA:VR-GREQ-299684_6j VR-GREQ-299684_6k VR-GREQ-299606_3 VR-GREQ-299606_4 VR-GREQ-299606_5 VR-GREQ-299606_7
and save it in a variable or something similar to it. Later I want to read CZM separately and so on. I did as below.
with open(output_filename, 'r') as f:
excel = f.read()
But how to read it separately ? can someone tell me how to do it ?

Something like this:
def read_file_with_custom_record_separator(file_path, delimiter='\n'):
fh = open(file_path)
data = ""
for line in fh:
if line.strip().endswith(delimiter) and data != "":
print "VARIABLE:\n<", data, ">\n"
data = line
else:
data += line
print "LAST VARIABLE:\n<", data, ">\n"
And then:
read_file_with_custom_record_separator("input.txt", ":")

You can make use of the file text : as indicator to create a new file like this:
savefilename = ""
with open(filename, 'r') as f:
for line in f:
line = line.strip() # get rid of the unnecessary white chars
lastchar = line[-1:] # get the last char
if lastchar == ":": # if the last char is ":"
savefilename = line[0:-1] # get file name from line (except the ":")
sf = open(savefilename + ".txt", 'w') # create a new file
else:
sf.write(line + "\n") # write the data to the opened file
Then you should get collection of files:
RRA.txt
CZM.txt
DUN.txt
# etc
which contains all the appropriate data:
RRA.txt
VR-GREQ-299684_6j
VR-GREQ-299684_6k
VR-GREQ-299606_3
VR-GREQ-299606_4
VR-GREQ-299606_5
VR-GREQ-299606_7
CZM.txt
VR-GREQ-299684_6k
VR-GREQ-299606_6
VR-GREQ-299606_8
VR-GREQ-299640_1
VR-GREQ-299640_5
VR-GREQ-299524_9
FB_65624_1
VR-GREQ-299680_5
DUN.txt
FB_71125_1
# and so on
You can replace the sf = open and the sf.write which whatever way you feel best to separate the data. Here, I use files...

You can iterate over the file and use the lines and indices to your advantage; something like this:
with open(output_filename, 'r') as f:
for index, line in enumerate(f):
# here you have access to each line and its index
# so you can save any number of lines you wish

What about reading it into a list, then process its element as you prefer
>>> f = open('myfile.txt', 'r').readlines()
>>> len(f)
46
>>> f[0]
RRA:
>>> f[-1]
VR-GREQ-299534_4
>>> f[:3]
['RRA:\n', 'VR-GREQ-299684_6j \n', 'VR-GREQ-299684_6k \n']
>>>
>>> [l for l in f if l.startswith('FB_')]
['FB_65624_1 \n', 'FB_71125_1 \n', 'FB_69228_1 \n', 'FB_65624_1 \n', 'FB_71125_1 \n', 'FB_71125_2 \n']
>>>

Problems with Python's file.write() method and string handling

The problem I am having at this point in time (being new to Python) is writing strings to a text file. The issue I'm experiencing is one where either the strings don't have linebreaks inbetween them or there is a linebreak after every character. Code to follow:
import string, io
FileName = input("Arb file name (.txt): ")
MyFile = open(FileName, 'r')
TempFile = open('TempFile.txt', 'w', encoding='UTF-8')
for m_line in MyFile:
m_line = m_line.strip()
m_line = m_line.split(": ", 1)
if len(m_line) > 1:
del m_line[0]
#print(m_line)
MyString = str(m_line)
MyString = MyString.strip("'[]")
TempFile.write(MyString)
MyFile.close()
TempFile.close()
My input looks like this:
1 Jargon
2 Python
3 Yada Yada
4 Stuck
My output when I do this is:
JargonPythonYada YadaStuck
I then modify the source code to this:
import string, io
FileName = input("Arb File Name (.txt): ")
MyFile = open(FileName, 'r')
TempFile = open('TempFile.txt', 'w', encoding='UTF-8')
for m_line in MyFile:
m_line = m_line.strip()
m_line = m_line.split(": ", 1)
if len(m_line) > 1:
del m_line[0]
#print(m_line)
MyString = str(m_line)
MyString = MyString.strip("'[]")
#print(MyString)
TempFile.write('\n'.join(MyString))
MyFile.close()
TempFile.close()
Same input and my output looks like this:
J
a
r
g
o
nP
y
t
h
o
nY
a
d
a
Y
a
d
aS
t
u
c
k
Ideally, I would like each of the words to appear on a seperate line without the numbers in front of them.
Thanks,
MarleyH

You have to write the '\n' after each line, since you're stripping the original '\n';
Your idea of using '\n'.join() doesn't work because it will use\n to join the string, inserting it between each char of the string. You need a single \n after each name, instead.
import string, io
FileName = input("Arb file name (.txt): ")
with open(FileName, 'r') as MyFile:
with open('TempFile.txt', 'w', encoding='UTF-8') as TempFile:
for line in MyFile:
line = line.strip().split(": ", 1)
TempFile.write(line[1] + '\n')

fileName = input("Arb file name (.txt): ")
tempName = 'TempFile.txt'
with open(fileName) as inf, open(tempName, 'w', encoding='UTF-8') as outf:
for line in inf:
line = line.strip().split(": ", 1)[-1]
#print(line)
outf.write(line + '\n')
Problems:
the result of str.split() is a list (this is why, when you cast it to str, you get ['my item']).
write does not add a newline; if you want one, you have to add it explicitly.