53 lines
1.5 KiB
Python
53 lines
1.5 KiB
Python
import csv
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from typing import Any, Callable, Iterable, Mapping, Optional, Sequence
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def convert_csv(
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lines: Iterable[str],
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conv: Callable[[Sequence[Any], Sequence[str]], Any],
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headers: Optional[Sequence[str]] = None,
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) -> Sequence[Any]:
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rows = csv.reader(lines)
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if headers is None:
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headers = next(rows)
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records = list(map(lambda row: conv(row, headers), rows))
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return records
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def csv_as_dicts(
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lines: Iterable[str], types: Sequence[type], headers: Optional[Sequence[str]] = None
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) -> Sequence[Mapping[str, Any]]:
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"""Parse CSV lines into a list of dictionaries."""
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def _conv(row, hdrs):
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return {name: func(val) for name, func, val in zip(hdrs, types, row)}
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return convert_csv(lines, _conv, headers)
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def read_csv_as_dicts(
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filename: str, types: Sequence[type], headers: Optional[Sequence[str]] = None
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) -> Sequence[Mapping[str, Any]]:
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"""
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Read CSV data into list of dictionaries with optional type conversion.
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"""
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with open(filename) as file:
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return csv_as_dicts(file, types, headers)
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def csv_as_instances(
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lines: Iterable[str], cls: type, headers: Optional[Sequence[str]] = None
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) -> Sequence[Any]:
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"""Parse CSV lines into a list of of class instances."""
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return convert_csv(lines, lambda row, _: cls.from_row(row), headers)
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def read_csv_as_instances(
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filename: str, cls: type, has_headers: bool = True
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) -> Sequence[Any]:
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"""
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Read CSV data into list of instances.
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"""
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with open(filename) as file:
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return csv_as_instances(file, cls, has_headers)
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