yf.download() not accepting custom period anymore → is this truly desired behavior?

[MichalRIcar]

Describe bug

I've been using yfinance for a few years now with the same syntax. However, the last updates changed the API.
Thus I wonder if download(period=X) is intentionally changed not to accept user defined period as it used to be and forcing to pre-defined "Valid periods"?

The orig. syntax
→ yf.download('^SPX', period='30d', interval='1h', ignore_tz = True, progress=False)
the orig. syntax produces error such as:
→ ...Period 'Xd' is invalid, must be one of ['1d', '5d', '1mo', '3mo', '6mo', '1y', '2y', '5y', '10y', 'ytd', 'max']")

The fix is to use start-end params. That is not a hard thing to do, but I think → shouldn't the yf API keep its behavior and compute start internally, whereas the end param = int(_time.time()), when the user sets a custom period rather than throwing an error?

Simple code that reproduces your problem

import yfinance  as yf

# worked for several years
yf.download('^SPX', period='30d', interval='1h', ignore_tz = True, progress=False)
# leads to: ...Period '30d' is invalid, must be one of ['1d', '5d', '1mo', '3mo', '6mo', '1y', '2y', '5y', '10y', 'ytd', 'max']") 

# newly forced to use start-end instead
# yf.download('^SPX', start = X, interval='1h', ignore_tz = True, progress=False)

Debug log

The bug is given by new syntax forcing user to use start-end instead of custom period.

Bad data proof

No response

yfinance version

0.2.40

Python version

3.12.4

Operating system

Win11

[ValueRaider]

yfinance hasn't changed handling period: https://github.com/ranaroussi/yfinance/blob/0.1.55/yfinance/base.py

yfinance isn't affiliated with Yahoo

[MichalRIcar]

Thanks, I am aware of independent dev of yfinance and appreciate it very much.
I've started observing the behavior (not accepting custom period anymore) a month ago.
As the fix in this case is truly trivial - to compute internally start param for a custom (not supported) period - I was thinking it's worth nothing to share the observation, rahter than just silently fix my pipeline.

[andrei-cb]

30d period is still working with version 0.2.18, looks like an issue with newer versions of yfinance

[ValueRaider]

It started with 0.2.32 when added cookie & crumb.