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Buffteks-Website/streamlit-venv/lib/python3.10/site-packages/narwhals/_arrow/utils.py
2025-01-10 21:40:35 +00:00

423 lines
15 KiB
Python
Executable File

from __future__ import annotations
from typing import TYPE_CHECKING
from typing import Any
from typing import Sequence
from narwhals.utils import isinstance_or_issubclass
if TYPE_CHECKING:
import pyarrow as pa
from narwhals._arrow.series import ArrowSeries
from narwhals.dtypes import DType
from narwhals.typing import DTypes
def native_to_narwhals_dtype(dtype: Any, dtypes: DTypes) -> DType:
import pyarrow as pa # ignore-banned-import
if pa.types.is_int64(dtype):
return dtypes.Int64()
if pa.types.is_int32(dtype):
return dtypes.Int32()
if pa.types.is_int16(dtype):
return dtypes.Int16()
if pa.types.is_int8(dtype):
return dtypes.Int8()
if pa.types.is_uint64(dtype):
return dtypes.UInt64()
if pa.types.is_uint32(dtype):
return dtypes.UInt32()
if pa.types.is_uint16(dtype):
return dtypes.UInt16()
if pa.types.is_uint8(dtype):
return dtypes.UInt8()
if pa.types.is_boolean(dtype):
return dtypes.Boolean()
if pa.types.is_float64(dtype):
return dtypes.Float64()
if pa.types.is_float32(dtype):
return dtypes.Float32()
# bug in coverage? it shows `31->exit` (where `31` is currently the line number of
# the next line), even though both when the if condition is true and false are covered
if ( # pragma: no cover
pa.types.is_string(dtype)
or pa.types.is_large_string(dtype)
or getattr(pa.types, "is_string_view", lambda _: False)(dtype)
):
return dtypes.String()
if pa.types.is_date32(dtype):
return dtypes.Date()
if pa.types.is_timestamp(dtype):
return dtypes.Datetime(time_unit=dtype.unit, time_zone=dtype.tz)
if pa.types.is_duration(dtype):
return dtypes.Duration(time_unit=dtype.unit)
if pa.types.is_dictionary(dtype):
return dtypes.Categorical()
if pa.types.is_struct(dtype):
return dtypes.Struct(
[
dtypes.Field(
dtype.field(i).name,
native_to_narwhals_dtype(dtype.field(i).type, dtypes),
)
for i in range(dtype.num_fields)
]
)
if pa.types.is_list(dtype) or pa.types.is_large_list(dtype):
return dtypes.List(native_to_narwhals_dtype(dtype.value_type, dtypes))
if pa.types.is_fixed_size_list(dtype):
return dtypes.Array(
native_to_narwhals_dtype(dtype.value_type, dtypes), dtype.list_size
)
return dtypes.Unknown() # pragma: no cover
def narwhals_to_native_dtype(dtype: DType | type[DType], dtypes: DTypes) -> Any:
import pyarrow as pa # ignore-banned-import
if isinstance_or_issubclass(dtype, dtypes.Float64):
return pa.float64()
if isinstance_or_issubclass(dtype, dtypes.Float32):
return pa.float32()
if isinstance_or_issubclass(dtype, dtypes.Int64):
return pa.int64()
if isinstance_or_issubclass(dtype, dtypes.Int32):
return pa.int32()
if isinstance_or_issubclass(dtype, dtypes.Int16):
return pa.int16()
if isinstance_or_issubclass(dtype, dtypes.Int8):
return pa.int8()
if isinstance_or_issubclass(dtype, dtypes.UInt64):
return pa.uint64()
if isinstance_or_issubclass(dtype, dtypes.UInt32):
return pa.uint32()
if isinstance_or_issubclass(dtype, dtypes.UInt16):
return pa.uint16()
if isinstance_or_issubclass(dtype, dtypes.UInt8):
return pa.uint8()
if isinstance_or_issubclass(dtype, dtypes.String):
return pa.string()
if isinstance_or_issubclass(dtype, dtypes.Boolean):
return pa.bool_()
if isinstance_or_issubclass(dtype, dtypes.Categorical):
return pa.dictionary(pa.uint32(), pa.string())
if isinstance_or_issubclass(dtype, dtypes.Datetime):
time_unit = getattr(dtype, "time_unit", "us")
time_zone = getattr(dtype, "time_zone", None)
return pa.timestamp(time_unit, tz=time_zone)
if isinstance_or_issubclass(dtype, dtypes.Duration):
time_unit = getattr(dtype, "time_unit", "us")
return pa.duration(time_unit)
if isinstance_or_issubclass(dtype, dtypes.Date):
return pa.date32()
if isinstance_or_issubclass(dtype, dtypes.List): # pragma: no cover
msg = "Converting to List dtype is not supported yet"
return NotImplementedError(msg)
if isinstance_or_issubclass(dtype, dtypes.Struct): # pragma: no cover
msg = "Converting to Struct dtype is not supported yet"
return NotImplementedError(msg)
if isinstance_or_issubclass(dtype, dtypes.Array): # pragma: no cover
msg = "Converting to Array dtype is not supported yet"
return NotImplementedError(msg)
msg = f"Unknown dtype: {dtype}" # pragma: no cover
raise AssertionError(msg)
def validate_column_comparand(other: Any) -> Any:
"""Validate RHS of binary operation.
If the comparison isn't supported, return `NotImplemented` so that the
"right-hand-side" operation (e.g. `__radd__`) can be tried.
If RHS is length 1, return the scalar value, so that the underlying
library can broadcast it.
"""
from narwhals._arrow.dataframe import ArrowDataFrame
from narwhals._arrow.series import ArrowSeries
if isinstance(other, list):
if len(other) > 1:
# e.g. `plx.all() + plx.all()`
msg = "Multi-output expressions are not supported in this context"
raise ValueError(msg)
other = other[0]
if isinstance(other, ArrowDataFrame):
return NotImplemented
if isinstance(other, ArrowSeries):
if len(other) == 1:
# broadcast
return other[0]
return other._native_series
return other
def validate_dataframe_comparand(
length: int, other: Any, backend_version: tuple[int, ...]
) -> Any:
"""Validate RHS of binary operation.
If the comparison isn't supported, return `NotImplemented` so that the
"right-hand-side" operation (e.g. `__radd__`) can be tried.
"""
from narwhals._arrow.dataframe import ArrowDataFrame
from narwhals._arrow.series import ArrowSeries
if isinstance(other, ArrowDataFrame):
return NotImplemented
if isinstance(other, ArrowSeries):
if len(other) == 1:
import pyarrow as pa # ignore-banned-import
value = other.item()
if backend_version < (13,) and hasattr(value, "as_py"): # pragma: no cover
value = value.as_py()
return pa.chunked_array([[value] * length])
return other._native_series
msg = "Please report a bug" # pragma: no cover
raise AssertionError(msg)
def horizontal_concat(dfs: list[Any]) -> Any:
"""
Concatenate (native) DataFrames horizontally.
Should be in namespace.
"""
import pyarrow as pa # ignore-banned-import
if not dfs:
msg = "No dataframes to concatenate" # pragma: no cover
raise AssertionError(msg)
names = [name for df in dfs for name in df.column_names]
if len(set(names)) < len(names): # pragma: no cover
msg = "Expected unique column names"
raise ValueError(msg)
arrays = [a for df in dfs for a in df]
return pa.Table.from_arrays(arrays, names=names)
def vertical_concat(dfs: list[Any]) -> Any:
"""
Concatenate (native) DataFrames vertically.
Should be in namespace.
"""
if not dfs:
msg = "No dataframes to concatenate" # pragma: no cover
raise AssertionError(msg)
cols = set(dfs[0].column_names)
for df in dfs:
cols_current = set(df.column_names)
if cols_current != cols:
msg = "unable to vstack, column names don't match"
raise TypeError(msg)
import pyarrow as pa # ignore-banned-import
return pa.concat_tables(dfs).combine_chunks()
def floordiv_compat(left: Any, right: Any) -> Any:
# The following lines are adapted from pandas' pyarrow implementation.
# Ref: https://github.com/pandas-dev/pandas/blob/262fcfbffcee5c3116e86a951d8b693f90411e68/pandas/core/arrays/arrow/array.py#L124-L154
import pyarrow as pa # ignore-banned-import
import pyarrow.compute as pc # ignore-banned-import
if isinstance(left, (int, float)):
left = pa.scalar(left)
if isinstance(right, (int, float)):
right = pa.scalar(right)
if pa.types.is_integer(left.type) and pa.types.is_integer(right.type):
divided = pc.divide_checked(left, right)
if pa.types.is_signed_integer(divided.type):
# GH 56676
has_remainder = pc.not_equal(pc.multiply(divided, right), left)
has_one_negative_operand = pc.less(
pc.bit_wise_xor(left, right),
pa.scalar(0, type=divided.type),
)
result = pc.if_else(
pc.and_(
has_remainder,
has_one_negative_operand,
),
# GH: 55561 ruff: ignore
pc.subtract(divided, pa.scalar(1, type=divided.type)),
divided,
)
else:
result = divided # pragma: no cover
result = result.cast(left.type)
else:
divided = pc.divide(left, right)
result = pc.floor(divided)
return result
def cast_for_truediv(arrow_array: Any, pa_object: Any) -> tuple[Any, Any]:
# Lifted from:
# https://github.com/pandas-dev/pandas/blob/262fcfbffcee5c3116e86a951d8b693f90411e68/pandas/core/arrays/arrow/array.py#L108-L122
import pyarrow as pa # ignore-banned-import
import pyarrow.compute as pc # ignore-banned-import
# Ensure int / int -> float mirroring Python/Numpy behavior
# as pc.divide_checked(int, int) -> int
if pa.types.is_integer(arrow_array.type) and pa.types.is_integer(pa_object.type):
# GH: 56645. # noqa: ERA001
# https://github.com/apache/arrow/issues/35563
return pc.cast(arrow_array, pa.float64(), safe=False), pc.cast(
pa_object, pa.float64(), safe=False
)
return arrow_array, pa_object
def broadcast_series(series: list[ArrowSeries]) -> list[Any]:
lengths = [len(s) for s in series]
max_length = max(lengths)
fast_path = all(_len == max_length for _len in lengths)
if fast_path:
return [s._native_series for s in series]
import pyarrow as pa # ignore-banned-import
is_max_length_gt_1 = max_length > 1
reshaped = []
for s, length in zip(series, lengths):
s_native = s._native_series
if is_max_length_gt_1 and length == 1:
value = s_native[0]
if s._backend_version < (13,) and hasattr(value, "as_py"): # pragma: no cover
value = value.as_py()
reshaped.append(pa.array([value] * max_length, type=s_native.type))
else:
reshaped.append(s_native)
return reshaped
def convert_slice_to_nparray(
num_rows: int, rows_slice: slice | int | Sequence[int]
) -> Any:
import numpy as np # ignore-banned-import
if isinstance(rows_slice, slice):
return np.arange(num_rows)[rows_slice]
else:
return rows_slice
def select_rows(table: pa.Table, rows: Any) -> pa.Table:
if isinstance(rows, slice) and rows == slice(None):
selected_rows = table
elif isinstance(rows, Sequence) and not rows:
selected_rows = table.slice(0, 0)
else:
range_ = convert_slice_to_nparray(num_rows=len(table), rows_slice=rows)
selected_rows = table.take(range_)
return selected_rows
def convert_str_slice_to_int_slice(
str_slice: slice, columns: list[str]
) -> tuple[int | None, int | None, int | None]:
start = columns.index(str_slice.start) if str_slice.start is not None else None
stop = columns.index(str_slice.stop) + 1 if str_slice.stop is not None else None
step = str_slice.step
return (start, stop, step)
# Regex for date, time, separator and timezone components
DATE_RE = r"(?P<date>\d{1,4}[-/.]\d{1,2}[-/.]\d{1,4})"
SEP_RE = r"(?P<sep>\s|T)"
TIME_RE = r"(?P<time>\d{2}:\d{2}:\d{2})" # \s*(?P<period>[AP]M)?)?
TZ_RE = r"(?P<tz>Z|[+-]\d{2}:?\d{2})" # Matches 'Z', '+02:00', '+0200', '+02', etc.
FULL_RE = rf"{DATE_RE}{SEP_RE}?{TIME_RE}?{TZ_RE}?$"
# Separate regexes for different date formats
YMD_RE = r"^(?P<year>(?:[12][0-9])?[0-9]{2})(?P<sep1>[-/.])(?P<month>0[1-9]|1[0-2])(?P<sep2>[-/.])(?P<day>0[1-9]|[12][0-9]|3[01])$"
DMY_RE = r"^(?P<day>0[1-9]|[12][0-9]|3[01])(?P<sep1>[-/.])(?P<month>0[1-9]|1[0-2])(?P<sep2>[-/.])(?P<year>(?:[12][0-9])?[0-9]{2})$"
MDY_RE = r"^(?P<month>0[1-9]|1[0-2])(?P<sep1>[-/.])(?P<day>0[1-9]|[12][0-9]|3[01])(?P<sep2>[-/.])(?P<year>(?:[12][0-9])?[0-9]{2})$"
DATE_FORMATS = (
(YMD_RE, "%Y-%m-%d"),
(DMY_RE, "%d-%m-%Y"),
(MDY_RE, "%m-%d-%Y"),
)
def parse_datetime_format(arr: pa.StringArray) -> str:
"""Try to infer datetime format from StringArray."""
import pyarrow as pa # ignore-banned-import
import pyarrow.compute as pc # ignore-banned-import
matches = pa.concat_arrays( # converts from ChunkedArray to StructArray
pc.extract_regex(pc.drop_null(arr).slice(0, 10), pattern=FULL_RE).chunks
)
if not pc.all(matches.is_valid()).as_py():
msg = (
"Unable to infer datetime format, provided format is not supported. "
"Please report a bug to https://github.com/narwhals-dev/narwhals/issues"
)
raise NotImplementedError(msg)
dates = matches.field("date")
separators = matches.field("sep")
times = matches.field("time")
tz = matches.field("tz")
# separators and time zones must be unique
if pc.count(pc.unique(separators)).as_py() > 1:
msg = "Found multiple separator values while inferring datetime format."
raise ValueError(msg)
if pc.count(pc.unique(tz)).as_py() > 1:
msg = "Found multiple timezone values while inferring datetime format."
raise ValueError(msg)
date_value = _parse_date_format(dates)
time_value = _parse_time_format(times)
sep_value = separators[0].as_py()
tz_value = "%z" if tz[0].as_py() else ""
return f"{date_value}{sep_value}{time_value}{tz_value}"
def _parse_date_format(arr: pa.Array) -> str:
import pyarrow.compute as pc # ignore-banned-import
for date_rgx, date_fmt in DATE_FORMATS:
matches = pc.extract_regex(arr, pattern=date_rgx)
if (
pc.all(matches.is_valid()).as_py()
and pc.count(pc.unique(sep1 := matches.field("sep1"))).as_py() == 1
and pc.count(pc.unique(sep2 := matches.field("sep2"))).as_py() == 1
and (date_sep_value := sep1[0].as_py()) == sep2[0].as_py()
):
return date_fmt.replace("-", date_sep_value)
msg = (
"Unable to infer datetime format. "
"Please report a bug to https://github.com/narwhals-dev/narwhals/issues"
)
raise ValueError(msg)
def _parse_time_format(arr: pa.Array) -> str:
import pyarrow.compute as pc # ignore-banned-import
matches = pc.extract_regex(arr, pattern=TIME_RE)
return "%H:%M:%S" if pc.all(matches.is_valid()).as_py() else ""