Type Casting

By default, fastpycsv.reader() returns strings. This matches Python’s standard library csv.reader() behavior and keeps parsing predictable.

Pass cast=True when you want csv-parser’s scalar classification surfaced as Python values:

import fastpycsv

reader = fastpycsv.reader(["id,amount,active\n", "1,2.5,true\n"], cast=True)
rows = list(reader)

assert reader.fieldnames == ["id", "amount", "active"]
assert rows[0].as_list() == [1, 2.5, True]

The mapping is:

CSV value classification	Python value
empty/null field	None
boolean	bool
integer	int
floating point	float
timestamp	datetime.datetime
string or mixed value	str

Use casting for exploratory data work and ETL scripts where Python values are more useful than raw strings. Keep the default string mode when exact textual round-tripping matters.