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by roelschroeven 513 days ago
I've often read that people have a problem with Python's startup time, but that's not at all my experience.

Yes, if you're going to import numpy or pandas or other heavy packages, that can be annoyingly slow.

But we're talking using Python as a bash script alternative here. That means (at least to me) importing things like subprocess, pathlib. In my experience, that doesn't take long to start.

$ cat helloworld.py #!/usr/bin/env python3 import subprocess from pathlib import Path print("Hello, world!\n")

$ time ./helloworld.py Hello, world!

real 0m0.034s user 0m0.016s sys 0m0.016s

34 milliseconds doesn't seem a lot of time to me. If you're going to run it in a tight loop than yes, that's going to be annoying, but in interactive use I don't even notice delays as small as that.

As for packaging complexity: when using Python as a bash script alternative, I mostly can easily get by with using only stuff from the standard library. In that case, packaging is trivial. If I do need other packages then yes, that can be major nuisance.
2 comments
BobbyTables2 513 days ago
Python startup time gets much worse on low powered ARM systems executing from an sdcard — before the first import even occurs!

It certainly takes more effort for this to be a problem on modern x86 systems.

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drdrey 513 days ago
once you start importing more packages, you easily end up with 100+ ms startup time
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robertlagrant 513 days ago
At that point you're far beyond a bash script alternative though, aren't you?
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ComputerGuru 512 days ago
Not necessarily. Shell scripts often embody the unix “do one thing and do it right” principle. To download a file in a bash script you wouldn’t (sanely) source a bash script that implements an http client;, you would just shell out to curl or wget. Same for parsing a json file/response: you would just depend on and defer to jq. Whereas in python you could do the same but most likely/idiomatically would pull in the imports to do that in python.

It’s what makes shell scripts so fast and easy for a lot of tasks.

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robertlagrant 512 days ago
Fair enough, although in your examples Python comes with JSON support, but not a (very usable) HTTP client, and Bash has the reverse problem.

I would like it if Python just had a sane nice HTTP client built in, but it can also just shell out to curl.

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