[New-bugs-announce] [issue45708] PEP 515-style formatting with underscores does not seem to work for Decimal

[Sander Bollen]

New submission from Sander Bollen <sander at sndrtj.eu>:

Hello,

It appears that Decimal does not support PEP-515 style formatting with underscores as thousands separators. 

```
>>> from decimal import Decimal
>>> f"{Decimal('5000'):,}"
'5,000'
>>> f"{Decimal('5000'):_}"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid format string

```

This does work for all the other types mentioned in PEP515

```
>>> f"{5000:_}"
'5_000'
>>> f"{5000.0:_}"
'5_000.0'
>>> f"{complex(5000, 1):_}"
'(5_000+1j)'
```

I have tried this on python 3.8, 3.9 and 3.10 on a Mac.

----------
components: Library (Lib)
messages: 405667
nosy: sndrtj
priority: normal
severity: normal
status: open
title: PEP 515-style formatting with underscores does not seem to work for Decimal
versions: Python 3.10, Python 3.8, Python 3.9

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue45708>
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