Number of decimal places with beanprice

[Alen Šiljak]

Hi! I've set up beanprice to fetch prices and that seems to work. I've also adapted some of my price sources to work with beancount. These are publicly available as as-price-download on github/pypi.

When running directly

```sh

bean-price -e "AUD:pricedl.beanprice.yahoo/ASX:VHY"

```

the price comes out as expected

```

2025-05-30 price ASX:VHY                             74.33 AUD

```

But, when reading the metadata from the book

```

bean-price -v ..\book.bean > ..\prices\prices.current.bean

```

the prices are coming out like this:

```

2025-05-30 price BLV                    67.6500000000000000000000000000 USD
2025-05-30 price BND                    72.6350000000000000000000000000 USD
2025-05-29 price BRF                    14.5922000000000000000000000000 USD
2025-05-30 price BSV                    78.2699966430664062500000000000 USD
2025-05-30 price CEMB                   44.8699989318847656250000000000 USD
2025-05-30 price CQE_AX                 2.960000038146972656250000000 AUD

```

These are from two different sources. Mine has 4 decimals, so likely using a different API.

Is there a way to limit the number of decimal places and/or to get rid of the zeros?

In the price source I've written, the price is Decimal type. So, the output and the conversion to string happens somewhere in beanprice, I assume?

Somebody elsewhere suggested that this is due to the existing prices and inference. I will try to experiment with one symbol.

Any hints highly appreciated!

[Chary Ev2geny]

Hi,

I also saw similar problem, so I now documented on how to reproduce it

https://github.com/beancount/beanprice/issues/116

Regards.

[Alen Šiljak]

Thank you for that analysis! 

For reference, I will also copy here the reply I added to that issue:

Thanks for elaborating! I had the same issue. However, I searched for decimal places
```sql
select * where round(number, 6) != number
```
and there was no records with that many decimal places. I looked for both `number` and `cost_number`.
I was debugging the `print` function but did not really figure out why all the prices were maxed-out with zeros. The currency precision was different for different currencies, while prices were all with almost the same number of decimal places.
After I fixed the price source to return the decimals as reported on the exchange (the source I was testing with was returning some crazy amounts with multiple decimals, but max. 6, not 18), the places were padded with 0's.
After reading your description, I assume the decimal places were jacked-up by implicit prices, since I'm using
```
plugin "beancount.plugins.implicit_prices"
```
in my book. But that is still just an assumption.

Based on the recent check-ins, Martin is working on the precision setting so that might eventually resolve the problem.

As a workaround, I wrote a simple script that strips the right-most zeros from the prices in the generated price file. This will work for now, as I'm focusing on completing the importers and other price sources.

[Chary Ev2geny]

I have create a simple PR 120, which I think fixes this (at least partially)

One can try it 

pip install git+https://github.com/Ev2geny/beanprice.git@issue_116