# fmt.fmt { #mlsysim.fmt.fmt }

```python
fmt.fmt(quantity, unit=None, precision=1, commas=True, prefix='', suffix='')
```

Format a Pint Quantity (or plain number) for narrative text.
Returns a MarkdownStr so Quarto inserts the value verbatim (no escape).

The prefix and suffix arguments collapse the old MarkdownStr(f"...")
escape-hatch idiom into a single canonical helper. Common uses:

    fmt(price, precision=0, prefix="$")         # "$1,000"
    fmt(rate * 100, precision=1, commas=False, suffix="%")  # "12.4%"
    fmt(bw_mb_s, precision=1, commas=False, suffix=" MB/s")  # "2.4 MB/s"
    fmt(speedup, precision=0, commas=False, suffix="x")     # "8x"

Safety: Raises ValueError if formatting would hide meaningful magnitude:
non-zero values displayed as ``0``, non-integers displayed with
``precision=0``, or integer-like values shown with spurious decimals
(``512.0``). Use ``fmt_int(...)`` when integer display is intentional.