I'm beginner in python
I have tried following code. When I run code it doesn't give error, however expected output must be in file, instead it prints output on console.
In actual test.txt file it make entries as 0.
Why does it print 0 and not the path returned by pwd command?
from subprocess import call
path = call('pwd')
with open('test.txt', "w") as f :
f.seek(0)
f.write(str(path))
f.close()
If you want to get output from an external command, use subprocess.check_output as noted by #Paul Rooney. You may change your program as follows to print the output of pwd to file:
from subprocess import check_output
path_bytes = check_output('pwd', shell=True)
path_str = path_bytes.decode('utf-8')
with open('test.txt', 'w') as f:
f.write(path_str)
Related
I'm trying to call a python script through incron:
/data/alucard-ops/drop IN_CLOSE_WRITE /data/alucard-ops/util/test.py $#/$#
but I cant seem to read from the file passed. Here is the script:
#!/usr/bin/env /usr/bin/python3
import os,sys
logfile = '/data/alucard-ops/log/'
log = open(logfile + 'test.log', 'a')
log.write(sys.argv[1] + "\n")
log.write(str(os.path.exists(sys.argv[1])) + "\n")
datafile = open(sys.argv[1], 'r')
log.write('Open\n')
data = datafile.readlines()
log.write("read\n")
datafile.close()
The output generated by the script:
/data/alucard-ops/drop/nsco-20180219.csv
True
Open
It seems to stop at the readlines() call. I dont see any errors in the syslog.
Update: It seems that i can use a subprocess to cat the file and it retrieves the contents. But, when i decode it, data.decode('utf-8') I'm back to nothing in the variable.
I ended up using watchdog instead.
I am able to save the cmd data onto a text file using the following command:
python code_3.py > output.txt
However I am calling code_3.py from primary_script.py by writing:
import code_3
os.system('loop3.py')
But I want it to perform the functionality of the what the previous line does. This doesn't work:
os.system('loop3.py > opt.txt ')
Can someone please tell me what to do?
Here's how to do it with the subprocess module:
import subprocess
import sys
p1 = subprocess.Popen([sys.executable, "loop3.py"], stdout=subprocess.PIPE)
output, err = p1.communicate()
with open('opt.txt', 'w') as file:
file.write(output.decode())
Is there a way to save all of the print output to a txt file in python? Lets say I have the these two lines in my code and I want to save the print output to a file named output.txt.
print ("Hello stackoverflow!")
print ("I have a question.")
I want the output.txt file to to contain
Hello stackoverflow!
I have a question.
Give print a file keyword argument, where the value of the argument is a file stream. The best practice is to open the file with the open function using a with block, which will ensure that the file gets closed for you at the end of the block:
with open("output.txt", "a") as f:
print("Hello stackoverflow!", file=f)
print("I have a question.", file=f)
From the Python documentation about print:
The file argument must be an object with a write(string) method; if it is not present or None, sys.stdout will be used.
And the documentation for open:
Open file and return a corresponding file object. If the file cannot be opened, an OSError is raised.
The "a" as the second argument of open means "append" - in other words, the existing contents of the file won't be overwritten. If you want the file to be overwritten instead at the beginning of the with block, use "w".
The with block is useful because, otherwise, you'd need to remember to close the file yourself like this:
f = open("output.txt", "a")
print("Hello stackoverflow!", file=f)
print("I have a question.", file=f)
f.close()
You can redirect stdout into a file "output.txt":
import sys
sys.stdout = open('output.txt','wt')
print ("Hello stackoverflow!")
print ("I have a question.")
Another method without having to update your Python code at all, would be to redirect via the console.
Basically, have your Python script print() as usual, then call the script from the command line and use command line redirection. Like this:
$ python ./myscript.py > output.txt
Your output.txt file will now contain all output from your Python script.
Edit:
To address the comment; for Windows, change the forward-slash to a backslash.
(i.e. .\myscript.py)
Use the logging module
def init_logging():
rootLogger = logging.getLogger('my_logger')
LOG_DIR = os.getcwd() + '/' + 'logs'
if not os.path.exists(LOG_DIR):
os.makedirs(LOG_DIR)
fileHandler = logging.FileHandler("{0}/{1}.log".format(LOG_DIR, "g2"))
rootLogger.addHandler(fileHandler)
rootLogger.setLevel(logging.DEBUG)
consoleHandler = logging.StreamHandler()
rootLogger.addHandler(consoleHandler)
return rootLogger
Get the logger:
logger = init_logging()
And start logging/output(ing):
logger.debug('Hi! :)')
Another Variation can be... Be sure to close the file afterwards
import sys
file = open('output.txt', 'a')
sys.stdout = file
print("Hello stackoverflow!")
print("I have a question.")
file.close()
Suppose my input file is "input.txt" and output file is "output.txt".
Let's consider the input file has details to read:
5
1 2 3 4 5
Code:
import sys
sys.stdin = open("input", "r")
sys.stdout = open("output", "w")
print("Reading from input File : ")
n = int(input())
print("Value of n is :", n)
arr = list(map(int, input().split()))
print(arr)
So this will read from input file and output will be displayed in output file.
For more details please see https://www.geeksforgeeks.org/inputoutput-external-file-cc-java-python-competitive-programming/
Be sure to import sys module. print whatever you want to write and want to save. In the sys module, we have stdout, which takes the output and stores it. Then close the sys.stdout . This will save the output.
import sys
print("Hello stackoverflow!" \
"I have a question.")
sys.stdout = open("/home/scilab/Desktop/test.txt", "a")
sys.stdout.close()
One can directly append the returned output of a function to a file.
print(output statement, file=open("filename", "a"))
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
Consider this snippet
from sys import argv
script, input_file = argv
def print_all(f):
print f.read()
current_file = open(input_file)
print_all(current_file)
Ref. line 4: Why do I have to use "print" along with "f.read()". When I use just f.read() it doesnt print anything, why ?
f.read() reads the file from disk into memory. print prints to the console. You will find more info on input and output in the documentation