Re: DataFrame.to_csv(quoting=csv.QUOTE_NONNUMERIC) quotes numeric values

[k-dahl]

As per the issue outlined in #12922, applying a float_format or having a NaN value with a float would continue to treat the value as non-numeric when quoting=csv.QUOTE_NONNUMERIC is used. The format string resulting in the float treated like a string should be documented as per @jreback in #12922.