timestamp() error on Windows with dates before 1970

[Biggels]

Hi there,

I'm working through your NBA example, and I'm noticing that anywhere where we're trying to use .timestamp(), e.g.

• t = datetime.strptime(row["date"], "%Y-%m-%d").timestamp()
• or when setting timestamps=True in the plotting (ts = [datetime.fromtimestamp(t) for t in ts])

it throws an error when encountering dates before 1970, as below:
OSError: [Errno 22] Invalid argument

This doesn't happen in the online notebook, and from some googling it sounds like it's a Windows specific issue. I was able to work around it in the main section by simply manually calculating the timedelta and converting it to seconds (t = (datetime.strptime(row["date"], "%Y-%m-%d") - datetime(1970, 1, 1)).total_seconds()), but that doesn't help me with the plotting, unfortunately.

Do you have any suggested workarounds or fixes? Let me know if any more info is needed.

Edit: To clarify, I'm running Python 3.8 in Spyder 4.1.1 on Windows

[spidy0x0]

i hope this helps,similar problem
https://stackoverflow.com/q/54470408/10346275

also,set your date back by 1 year and try again

[lucasmaystre]

Hi @Biggels , apologies for the delay (and thank you @spidyhackx for helping out.)

Thanks for reporting. I don't have access to a Windows machine, so it is difficult for me to debug this. I'm glad you were able to work around it in the main notebook.

For the plotting: an easy fix would be to call plot_scores with timestamps=False. This function returns fig, ax, so you could always use ax.set_xticklabels() as needed to create a pretty plot.

Would the following change in plot_scores fix things on windows?

ts = [datetime(1970, 1, 1) + t for t in ts]

[Biggels]

Thanks for the tip on setting ticklabels manually. Seems obvious in hindsight :)

As for your suggested change, I don't believe you can add a float directly to a datetime object. From some testing, it looks like you have to convert the float time in seconds to a timedelta object first. The following snippet, for example, worked for me to convert all the float times in my dictionary of observations to datetime objects:

from datetime import datetime, timedelta
ts = [observation['t'] for observation in observations]
ts = [datetime(1970, 1, 1) + timedelta(seconds=t) for t in ts]

[lucasmaystre]

Ah, yes, makes sense. OK, I'll change this in the plotting function 👍