Hi I am trying to schedule job using crontab in ubuntu machine I have written python codes to extract .csv file from the given data.
The codes are working fine and returning .csv file when I type in the command python3 app.py in the Terminal(CMD) of Ubuntu machine.
But when i schedule a Job using crontab the file is being executed but it is not returning the expected .csv file.
The crontab is working fine when i type in 45 14 * * * bash./home/test1.sh>myfile.sh it is returning myfile.sh(which is a shell script file)
When i try to run python3 app.py the codes are being executed but it is not returning the expected .csv file. The command I used is
55 15 * * * python3 ./Documents/user/app.py
I want this code to return .csv file but it is not returning any file. where did I go wrong
kindly help on this regard.
I have a simple Python script on EC2 to write a text to a file:
with open("/home/ec2-user/python/test.txt", "a") as f:
f.write("test\n\n")
That python script is here:
/home/ec2-user/python/write_file.py
When I run that script manually ('python /home/ec2-user/python/write_file.py') - new text is being written to a file ('/home/ec2-user/python/test.txt').
When schedule same script using Cronjob - no data is being added to a file. My Cronjob looks like this:
* * * * * python /home/ec2-user/python/write_file.py
I verify Cronjob is running and suspecting some ENV parameters are not the same during Cronjob execution (or something else is happening). What could be the case and how to fix it in a simple way?
Thanks.
I recently began using Amazon's linux distro on ec2 instances and after trying all kinds of things for cron all I needed was:
sudo service crond start
crontab -e
This allowed me to set a cron job as "ec2-user" without specifying the user or env variables or anything. For example, this single line worked:
0 12 * * * python3 /home/ec2-user/example.py
I also posted this here.
On crontab
HOME=/home/ec2-user/
* * * * * python /home/ec2-user/python/write_file.py
alternatively (testing purpose)
* * * * * root /home/ec2-user/python/write_file.py
On your write_file.py add shebang (first line)
#!/usr/bin/env python
BONUS: (feel free to ignore) my first response debug method for cron on minute tasks:
import os
while True:
print os.popen('pgrep -lf python').read()
executed from shell will pop out all python modules called by cron. After 60 secs you know whats going on.
it's bette to specify the absolute path of the python interpreter because the command may not be recognized by the system. Or you can add the shebang line to your script #!pathToPythonInterpreter at the first line of your script
make sure that the user who planning the execution of script have the right to read and write to the file
make sure that you are not using the system corntab /etc/crontab to planify because then you have to specify the user who will execute the command.
I hope that this will help you
I want a python webscraping program to be run everyday at a certain time. For that i am using this command in the cron in ubuntu
28 22 * * * root /home/ahmed/Desktop python hello.py
It just doesnt work. there must be something wrong with it. can anyone help me please?
Try adding #!/usr/bin/python (called shebang line) to the top of your Python script and then
28 22 * * * root /home/ahmed/Desktop/hello.py
You have to make your script executable like this (run this as a separate command):
sudo chmod +x /home/ahmed/Desktop/hello.py
From the Shebang page on Wikipedia:
Under Unix-like operating systems, when a script with a shebang is run
as a program, the program loader parses the rest of the script's
initial line as an interpreter directive; the specified interpreter
program is run instead, passing to it as an argument the path that was
initially used when attempting to run the script.[8] For example, if a
script is named with the path "path/to/script", and it starts with the
following line:
#!/bin/sh then the program loader is instructed to run the program "/bin/sh" instead (usually this is the Bourne shell or a compatible
shell), passing "path/to/script" as the first argument.
If you don't want to change anything this will work as well:
28 22 * * * root python /home/ahmed/Desktop/hello.py
/home/ahmed/Desktop is (most probably!) not a valid command name. You want
28 22 * * * root python hello.py
or possibly
28 22 * * * root python /home/ahmed/Desktop/hello.py
depending somewhat on why you put that folder name there.
The syntax of a regular user's crontab is different. I can imagine no legitimate reason to run a scaping program as root. To run it from your own crontab you should use
28 22 * * * python /home/ahmed/Desktop/hello.py
(again possibly without the path name, or with the path somewhere else in the command line).
This question already has answers here:
CronJob not running
(19 answers)
Closed 2 years ago.
My python script is not running under my crontab.
I have placed this in the python script at the top:
#!/usr/bin/python
I have tried doing this:
chmod a+x myscript.py
Added to my crontab -e:
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=""
* * * * * /home/me/project/myscript.py
My /var/log/cron file says:
Sep 21 11:53:02 163-dhcp /USR/SBIN/CROND[2489]: (me) CMD (/home/me/project/myscript.py)
But my script is not running because when I check my sql database, nothing has changed. If I run it directly in the terminal like so:
python /home/me/project/myscript.py
I get the correct result.
This is the myscript.py:
#!/usr/bin/python
import sqlite3
def main():
con = sqlite3.connect("test.db")
with con:
cur = con.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS testtable(Id INTEGER PRIMARY KEY, Name TEXT)")
cur.execute("INSERT INTO testtable(Name) VALUES ('BoB')")
cur.execute("SELECT * FROM testtable")
print cur.fetchall()
if __name__ == "__main__":
main()
Per comments: Yes, /usr/bin/python exists. I can also run the python script directly using just /home/me/project/myscript.py. /usr/bin/python /home/me/project/myscript.py works. So I don't believe this is the cause?
There are a lot of half answers across the internet so I thought I would capture this to save someone else some time.
First, cronjob does a poor job of telling you where this is failing. I recommend sending stderr output to a log file like this:
Crontab Command:
# m h dom mon dow command
* * * * * /path/to/your_file.sh >> out.txt 2>&1
As this is likely running the command as user, check home directory for the log file. Note this script runs every minute which is good for debugging.
The next issue is you probably have a path problem... as script likely is trying to execute from your home directory. This script sets the current directory, echos it to file, and then runs your program.
Try this :
Script File
#!/bin/sh
cd "$(dirname "$0")";
CWD="$(pwd)"
echo $CWD
python your_python_file.py
Hope this saves someone else some debugging time!!!
What happens when you type
/home/me/project/myscript.py into the shell?
Can you explicitly use /usr/bin/python in your crontbb command?
Can you either use an absolute path to your test.db or cd to the correct directory then execute your python script?
This is helpful to have debug statements in your python and log some data. Crontab can be very tricky to debug.
It is possible that the script does not start because it cannot locate the python interpreter. Crontab environment may be very different from the shell environment which you are using. The search paths may be differ significantly.
Also, you test your script by starting the python interpreter explicitly while you expect the crontab to only start the script.
I put this line at the top of my python scripts:
\#!/bin/env python
This line will help locate the interpreter regardless of which directory it is installed in as long as it is in the search path.
It's usually because the python used by crontab is different from the one you use in the shell.
The easiest way to solve this is:
get the python you use in the shell:
$ which python # it may be "python3" or something else
/usr/bin/python
use that specific python in crontab file:
* * * * * /usr/bin/python test.py
Also want to mention that using env -i /bin/bash --noprofile --norc in the shell lets you have the same environment as the one used by crontab, and this is super helpful to debug.
Typically, crontab problems like this are caused by the PATH environment variable being more restrictive/different than what your normal user's PATH environment is. Since your shell uses the PATH environment to find the executable (e.g. /usr/bin/python is found in /usr/bin when you type "python" at a shell prompt), when the PATH is missing common locations, like /usr/bin or /usr/sbin, your cron job will fail. This has bit me many times. The simple fix is just to explicitly set the PATH yourself near the top of your crontab file, before any commands that need it. So, just edit the crontab as usual and add something like this near the top (if your binary is not in one of the below paths, you'll need to add it after a colon):
PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin
Alternately, just use absolute paths to your binaries and scripts in crontab.
Try this
* * * * * cd <directory_where_python_file_is> && bin/app etc/app_defaults.yaml
There is some path issue with cron. So when you move to directory with python file, cron works like charm!
I'd got the same problem. Despite the fact that the script executed manually was working, in crontab no options mentioned above were working at all. I've moved my script from /home/user/script_directory/ to /opt/scripts/ and it started to work. Possible cause of the problem should be the access (read) permissions to subfolder located in home directory.
Easiest way to handle this is to add your python installation's path to PATH in top of the shell script.
Something like:
#!/usr/bin/env bash
export PATH="{path to your python installation}:$PATH"
python {python_file_name}.py
As #Shargors said you can test it by
env -i /bin/bash --noprofile --norc
If you are using anaconda for python then the path to use will be :
/home/username/anaconda3/bin/python test.py
While the answers here clearly delineate the problem and solution, I wanted to add another answer which helped me.
If your python script is calling a database, then be sure you can connect to the db properly within the cron env (to identify the cron env--> https://askubuntu.com/questions/23009/reasons-why-crontab-does-not-work). I had a file that would run from the shell, but not as a crontab unless I connected to the database as root from within the python script.
Sometimes I am facing same problem. Whatever I try something as advised here, I may not get result.
So I begin to write "trigger" bash script as follow (let's name it trigger.sh):
#!/bin/bash
/full_path/python_script.py
And I am calling trigger.sh from crontab and everything is fine.
EDIT: Of course, don't forget to do following (give execution right):
$chmod +x python_script.py
$chmod +x trigger.sh
I was working on project that includes paramiko lib, when I run the Check_.py from cmdlin it works perfect but when I set the crontab it fails with error no module name paramiko.
So to make it short:
- there were two different python versions installed 3.7 and 2.4, so I used whreris python3 to locate the python path /usr/local/bin/python3.7m so replacing the python with the path will solve the issue.
Example
* * * * * cd /home/MKhair/hlthchk/BR/ && /usr/local/bin/python3.7m /home/MKhair/hlthchk/BR/Check_.py
* * * * * cd [ path-to-the-script-dir] && [path-to-python] [path-to-the-script]
Try to put in your crontab:
* * * * * python /path/to/your/script.py
rather than
* * * * * /path/to/your/script.py
Also the shebang line is #!/usr/bin/env python in some environments. env is an executable, and you have to know where it lives with "$ which env".
Is the cron user (where the script fails) and the terminal user (when the script succeeds) are same ?
Can you redirect the job output to some file as mentioned in Cron Job Log - How to Log?. We could see whether that helps.
This might be helpful for someone. I was having this same issue (or at least a similar issue) and what helped me was to get the path in which Python (Be aware of the version you want to use python, python3, etc...) by running this:
which python3
And then, I replaced python3 for the full path of python3 in my crontab file.
/bin/sh: /Users/alex/filename.py: No such file or directory
I have set a cronjob and it runs at the right time but the script isn't getting executed. When I check the mail I get that error. Both the script and the cronjob file are in:
/Users/alex
My cronjob file looks like this:
45 19 * * * /Users/alex/filename.py
I know the script works because I can launch it manually from the terminal.
Where am I screwing this up?
Try this:
45 19 * * * /path/to/python /Users/alex/filename.py
where path/to/python is something like /usr/bin/python (default on OS X I believe).
Are you sure it Users and not users? Does your filename.py have execute permission for cron?