问题
I can run multiple Python scripts simultaneously from a bash script like this;
#!/bin/bash
python pr1.py &
python pr2.py &
python aop.py &
python loader.py &
But what if I want a batch to fire simultaneously and after they've run, start some more sequentially. Will this work?:
#!/bin/bash
python pr1.py &
python pr2.py &
python ap.py &
python loader.py
python cain.py
python able.py
回答1:
On your bash script you can simply add the wait command like this:
#!/bin/bash
python pr1.py &
python pr2.py &
python ap.py &
wait
python loader.py
python cain.py
python able.py
wait will, obviously, wait for all the jobs (the background proccess you fired) to be finished for it to continue.
回答2:
Once you put & at the end, it runs as a background process. Hence all the scripts ending with & run in parallel.
To run the other 3 scripts in sequential order you can try both:
&& runs the next script only if the preceding script has run successfully
python loader.py && python cain.py && python able.py
|| runs scripts sequentially irrespective of the result of preceding script
python loader.py || python cain.py || python able.py
回答3:
With the & command you are running the scripts in the background. you could add a check in a loop to run the command jobs and see if it continues to return a list of jobs. when it stops you can continue with your next batch of python calls.
回答4:
Why not try it out ?
#1.py
import time
time.sleep(3)
print("First script")
#2.py
import time
time.sleep(3)
print("Second script")
If you put the processes into background, you will see the output from both the python scripts at the same time.
#!/bin/bash
python 1.py &
python 2.py &
If you execute it without the &, then you will see the output from the second script after 6 seconds.
#!/bin/bash
python 1.py
python 2.py
PS: Be careful to take care of dependencies and concurrent access issues while running it in parallel
来源：https://stackoverflow.com/questions/42072715/running-multiple-python-scripts-simultaneously-and-then-sequentially