为什么导入 openpyxl 需要这么长时间？

Question

I wrote a GUI program using python tkinter and noticed it's extremely slow to start up, it took 8 seconds for the window to show up! I checked the code and finally found it's because of an Excel read/write module named openpyxl . When I commented out thie line: import openpyxl . The GUI window show up instantly.

I also tried to run code import openpyxl on python prompt and it nearly took 3 seconds to finish running the code!

Is this normal take so long to load this module?

PS: i'm using openpyxl 3.0.2

Answer 1

I don't know outright why it's so slow, however I do know that it simply is. You can try using a code profiler (like in PyCharm) to find out what exactly takes so long, or you can improve user experience by importing the module at runtime whenever you need it.

Take the following:

import openpyxl


... gui stuff


def on_button_clicked():
    openpyxl.do_something()
    ...done

The following code would take ages to load up for the user, changing it to the following would drastically improve startup performance and lead to a better user experience.

Do note that at the end of the day the code would still take 3 seconds to load, but you're moving it to a place where people don't mind it to happen as they expect things to take a little longer if they press a button and a loader gets shown

... gui stuff


def on_button_click():
    ... show a loader or something
    import openpyxl
    openpyxl.do_something()
    ... done