Add more specific error throwing based on PR 1918

[marcofognog]

Closes #270 and #1925

Purpose

It is useful to have the lib to throw specific errors for each failure, instead of the generic Exception.

With the error types being thrown, clients can chose to handle each failure scenario in different ways.

Ex:

    try:
        hist = ticker.history(period=period, interval=interval, raise_errors=True)
    except YFPricesMissingError as ex: 
            flash('The provided ticker symbol was not found, perhaps you mispelled it?')
    except YFInvalidPeriodError
            flash('Please provide a valid period')
            return redirect('/')

Backwards compatility

Because currently the exception being raise is the type Exception, we can safely assume no one is rescuing any of those new types. If any one is rescuing Exception code will continue to work in the same way.

Notes

This PR is basically the same as #1918 except I rebased to current dev and implemented changes suggested on the original PR.

I also tested it with my client app and it works as expected.

[paulmcq]

Typo:
'''class YFTickerMissingError(YFException):
def init(self, ticker, rationale):
super().init(f"${ticker}: possibly delisted; {rationale}")
self.rationale = rationale
self.ticker = ticker ## rationale
'''

[marcofognog]

Typo: '''class YFTickerMissingError(YFException): def init(self, ticker, rationale): super().init(f"${ticker}: possibly delisted; {rationale}") self.rationale = rationale self.ticker = ticker ## rationale '''

I'm sorry, I still can't see the typo, could you be more specific?

[paulmcq]

At line 25 of yfinance/exceptions.py. the new code says self.ticker = rationale but surely that should be self.ticker = ticker because line 24 is self.rationale = rationale Sorry I was not more explicit.

[marcofognog]

At line 25 of yfinance/exceptions.py. the new code says self.ticker = rationale but surely that should be self.ticker = ticker because line 24 is self.rationale = rationale Sorry I was not more explicit.

Good catch! Thank you very much.

[marcofognog]

FYI @elibroftw

[ValueRaider]

Final point: can you git-squash some commits to shorten history, at least your last few commits? Helps this https://github.com/ranaroussi/yfinance/network

[marcofognog]

Final point: can you git-squash some commits to shorten history, at least your last few commits? Helps this https://github.com/ranaroussi/yfinance/network

Sure. I'm squashing only mine to not loose the author on the previous commits.

[paulmcq]

Line 25 of exceptions.py is still wrong:
#1928 (comment)

[ValueRaider]

yfinance/yfinance/exceptions.py

Line 25 in 0493373

self.ticker = ticker

Looks fine to me

[paulmcq]

You are correct. I was apparently looking at the wrong version. Please excuse the spam.