Develop Reference

How to access CSV file using OS module

How do I access a CSV file on my computer in Jupyter notebook using os module?
I've tried the below code:
import os
file =
(r"C:\Users\...", "r")
text = file.read()
file.close

You can use it directly without os module:
with open(r"C:\Users\xyz\Desktop\test.csv","r") as f1:
lines = f1.readlines()
OR
f = open(r"C:\Users\xyz\Desktop\test.csv", "r")

You don't need to manually open and close the file, the keyword 'with' does that for you:
import csv
file = r'path\to\your.csv'
with open(file, 'r') as csvfile:
# do something
For more info please check the official documentation of the CSV module.

Python results output to txt file

I tried this code posted 2 years ago:
import subprocess
with open("output.txt", "wb") as f:
subprocess.check_call(["python", "file.py"], stdout=f)
import sys
import os.path
orig = sys.stdout
with open(os.path.join("dir", "output.txt"), "wb") as f:
sys.stdout = f
try:
execfile("file.py", {})
finally:
sys.stdout = orig
It hangs up the terminal until I ctl-z and then it crashes the terminal but prints the output.
I'm new to coding and am not sure how to resolve. I'm obviously doing something wrong. Thanks for your help.

You can simply open and write to the file with write.
with open('output.txt', 'w') as f:
f.write('output text') # You can use a variable from other data you collect instead if you would like
Since you are new to coding, i'll just let you know that opening a file using with will actually close it automatically after the indented code is ran. Good luck with your project!

How to open a file of different extension with notepad in python

I have a .fhx file that I could open normally with notepad but I want to open it using Python. I have tried subprocess.popen which I got online but I keep getting errors. I also want to be able to read the contents of this file like a normal text file like how we do in f=open("blah.txt", "r") and f.read(). Could anyone guide me in the right direction ?
import subprocess
filepath = "C:\Users\Ch\Desktop\FHX\fddd.fhx"
notePath = r'C:\Windows\System32\notepad.exe'
subprocess.Popen("%s %s" % (notePath, filepath))

Solved my problem by adding encoding="utf16" to the file open command.
count = 1
filename = r'C:\Users\Ch\Desktop\FHX\27-ESDC_CM02-2.fhx'
f = open(filename, "r", encoding="utf16") #Does not work without encoding
lines = f.read().splitlines()
for line in lines:
if "WIRE SOURCE" in line:
liner = line.split()
if any('SOURCE="INPUT' in s for s in liner):
print(str(count)+") ", "SERIAL INPUT = ", liner[2].replace("DESTINATION=", ""))
count += 1
Now I'm able to get the data the way I wanted.Thanks everyone.

try with shell=True argument
subprocess.call((notePath, filepath), shell=True )

You should be passing a list of args:
import subprocess
filepath = r"C:\Users\Ch\Desktop\FHX\fddd.fhx"
notePath = r'C:\Windows\System32\notepad.exe'
subprocess.check_call([notePath, filepath])
If you want to read the contents then just open the file using open:
with open(r"C:\Users\Ch\Desktop\FHX\fddd.fhx") as f:
for line in f:
print(line)
You need to use raw string for the path also to escape the f n your file path name, if you don't you are going to get errors.
In [1]: "C:\Users\Ch\Desktop\FHX\fddd.fhx"
Out[1]: 'C:\\Users\\Ch\\Desktop\\FHX\x0cddd.fhx'
In [2]: r"C:\Users\Ch\Desktop\FHX\fddd.fhx"
Out[2]: 'C:\\Users\\Ch\\Desktop\\FHX\\fddd.fhx'

How to execute a python script and write output to txt file?

I'm executing a .py file, which spits out a give string. This command works fine
execfile ('file.py')
But I want the output (in addition to it being shown in the shell) written into a text file.
I tried this, but it's not working :(
execfile ('file.py') > ('output.txt')
All I get is this:
tugsjs6555
False
I guess "False" is referring to the output file not being successfully written :(
Thanks for your help

what your doing is checking the output of execfile('file.py') against the string 'output.txt'
you can do what you want to do with subprocess
#!/usr/bin/env python
import subprocess
with open("output.txt", "w+") as output:
subprocess.call(["python", "./script.py"], stdout=output);

This'll also work, due to directing standard out to the file output.txt before executing "file.py":
import sys
orig = sys.stdout
with open("output.txt", "wb") as f:
sys.stdout = f
try:
execfile("file.py", {})
finally:
sys.stdout = orig
Alternatively, execute the script in a subprocess:
import subprocess
with open("output.txt", "wb") as f:
subprocess.check_call(["python", "file.py"], stdout=f)
If you want to write to a directory, assuming you wish to hardcode the directory path:
import sys
import os.path
orig = sys.stdout
with open(os.path.join("dir", "output.txt"), "wb") as f:
sys.stdout = f
try:
execfile("file.py", {})
finally:
sys.stdout = orig

If you are running the file on Windows command prompt:
python filename.py >> textfile.txt
The output would be redirected to the textfile.txt in the same folder where the filename.py file is stored.
The above is only if you have the results showing on cmd and you want to see the entire result without it being truncated.

The simplest way to run a script and get the output to a text file is by typing the below in the terminal:
PCname:~/Path/WorkFolderName$ python scriptname.py>output.txt
*Make sure you have created output.txt in the work folder before executing the command.

Use this instead:
text_file = open('output.txt', 'w')
text_file.write('my string i want to put in file')
text_file.close()
Put it into your main file and go ahead and run it. Replace the string in the 2nd line with your string or a variable containing the string you want to output. If you have further questions post below.

file_open = open("test1.txt", "r")
file_output = open("output.txt", "w")
for line in file_open:
print ("%s"%(line), file=file_output)
file_open.close()
file_output.close()

using some hints from Remolten in the above posts and some other links I have written the following:
from os import listdir
from os.path import isfile, join
folderpath = "/Users/nupadhy/Downloads"
filenames = [A for A in listdir(folderpath) if isfile(join(folderpath,A))]
newlistfiles = ("\n".join(filenames))
OuttxtFile = open('listallfiles.txt', 'w')
OuttxtFile.write(newlistfiles)
OuttxtFile.close()
The code above is to list all files in my download folder. It saves the output to the output to listallfiles.txt. If the file is not there it will create and replace it with a new every time to run this code. Only thing you need to be mindful of is that it will create the output file in the folder where your py script is saved. See how you go, hope it helps.

You could also do this by going to the path of the folder you have the python script saved at with cmd, then do the name.py > filename.txt
It worked for me on windows 10

how to send the output of pprint module to a log file

I have the following code:
logFile=open('c:\\temp\\mylogfile'+'.txt', 'w')
pprint.pprint(dataobject)
how can i send the contents of dataobject to the log file on the pretty print format ?

with open("yourlogfile.log", "w") as log_file:
pprint.pprint(dataobject, log_file)
See the documentation.

Please use pprint.pformat, which returns a formated string that can be dumped directly to file.
>>> import pprint
>>> with open("file_out.txt", "w") as fout:
... fout.write(pprint.pformat(vars(pprint)))
...
Reference:
http://docs.python.org/2/library/pprint.html

For Python 2.7
logFile = open('c:\\temp\\mylogfile'+'.txt', 'w')
pp = pprint.PrettyPrinter(indent=4, stream=logFile)
pp.pprint(dataobject) #you can reuse this pp.print