pocketutils.tools.common_tools.CommonTools.is_float() - Code Metrics - Inspection of "feat: misc" - dmyersturnbull/pocketutils - Measure and Improve Code Quality continuously with Scrutinizer

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by Douglas

created 2021-11-01 01:13 UTC

CommonTools.is_float() A

↳ Parent: pocketutils.tools.common_tools

Complexity

Conditions

Size

Total Lines	10
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	2
eloc	7
nop	2
dl	0
loc	10
rs	10
c	0
b	0
f	0

import sys

from collections import defaultdict
from typing import (
    Any,
    Callable,
    Generator,
    Iterable,
    Iterator,
    Mapping,
    Optional,
    Sequence,
    Tuple,
    Type,
    TypeVar,
    Union,
)

import pandas as pd


from pocketutils.core._internal import nicesize

from pocketutils.core.exceptions import RefusingRequestError, XKeyError, XValueError

from pocketutils.core.input_output import DevNull

from pocketutils.tools.base_tools import BaseTools

Y = TypeVar("Y")

T = TypeVar("T")

Z = TypeVar("Z")

Q = TypeVar("Q")



class CommonTools(BaseTools):

    @classmethod
    def limit(cls, items: Iterable[Q], n: int) -> Generator[Q, None, None]:

        for i, x in zip(range(n), items):

            yield x

    @classmethod
    def is_float(cls, s: Any) -> bool:

        """
        Returns whether ``float(s)`` succeeds.
        """
        try:
            float(s)
            return True
        except ValueError:
            return False

    @classmethod
    def try_none(
        cls,

        function: Callable[[], T],

        fail_val: Optional[T] = None,

        exception=Exception,

    ) -> Optional[T]:
        """
        Returns the value of a function or None if it raised an exception.

        Args:
            function: Try calling this function
            fail_val: Return this value
            exception: Restrict caught exceptions to subclasses of this type
        """
        # noinspection PyBroadException
        try:
            return function()
        except exception:

            return fail_val

    @classmethod
    def succeeds(cls, function: Callable[[], Any], exception=Exception) -> bool:
        """Returns True iff ``function`` does not raise an error."""
        return cls.try_none(function, exception=exception) is not None

    @classmethod
    def or_null(cls, x: Any, dtype=lambda s: s, or_else: Any = None) -> Optional[Any]:

        """
        Return ``None`` if the operation ``dtype`` on ``x`` failed; returns the result otherwise.
        """
        return or_else if cls.is_null(x) else dtype(x)

    @classmethod
    def or_raise(

        cls,

        x: Any,

        dtype=lambda s: s,

        or_else: Union[None, BaseException, Type[BaseException]] = None,

    ) -> Any:
        """
        Returns ``dtype(x)`` if ``x`` is not None, or raises ``or_else``.
        """
        if or_else is None:
            or_else = LookupError(f"Value is {x}")
        elif isinstance(or_else, type):
            or_else = or_else(f"Value is {x}")
        if cls.is_null(x):
            raise or_else
        return dtype(x)

    @classmethod
    def iterator_has_elements(cls, x: Iterator[Any]) -> bool:

        """
        Returns False iff ``next(x)`` raises a ``StopIteration``.
        WARNING: Tries to call ``next(x)``, progressing iterators. Don't use ``x`` after calling this.

        Note that calling ``iterator_has_elements([5])`` will raise a `TypeError`

        Args:
            x: Must be an Iterator
        """
        return cls.succeeds(lambda: next(x), StopIteration)

    @classmethod
    def is_null(cls, x: Any) -> bool:

        """
        Returns True if:
            - x is ``None``
            - x is ``float('NaN')``
            - ``pd.isna(x)``
        """
        try:
            if pd.isna(x):
                return True
        except (ValueError, TypeError):
            pass
        return x is None or x == float("NaN")

    @classmethod
    def is_empty(cls, x: Any) -> bool:

        """
        Returns True iff either:
            - x is None
            - pd.is_na(x)
            - x is something with 0 length
            - x is iterable and has 0 elements (will call ``__iter__``)

        Raises:
            RefusingRequestError If ``x`` is an Iterator. Calling this would empty the iterator, which is dangerous.

        """
        if isinstance(x, Iterator):

            raise RefusingRequestError("Do not call is_empty on an iterator.")
        try:
            if pd.isna(x):
                return True
        except (ValueError, TypeError):
            pass
        return (
            x is None
            or x == float("NaN")
            or hasattr(x, "__len__")
            and len(x) == 0
            or hasattr(x, "__iter__")
            and len(list(iter(x))) == 0
        )

    @classmethod
    def is_probable_null(cls, x: Any) -> bool:

        """
        Returns True iff either:
            - x is None
            - pd.isna(x)
            - x is something with 0 length
            - x is iterable and has 0 elements (will call ``__iter__``)
            - a str(x) is 'nan', 'n/a', 'null', or 'none'; case-insensitive

        Things that are **NOT** probable nulls:
            - "na"
            - 0
            - [None]

        Raises:
            TypeError If ``x`` is an Iterator.
                      Calling this would empty the iterator, which is dangerous.
        """
        return cls.is_empty(x) or str(x).lower() in ["nan", "n/a", "null", "none"]

    @classmethod
    def unique(cls, sequence: Iterable[T]) -> Sequence[T]:
        """
        Returns the unique items in `sequence`, in the order they appear in the iteration.

        Args:
            sequence: Any once-iterable sequence

        Returns:
            An ordered List of unique elements
        """
        seen = set()
        return [x for x in sequence if not (x in seen or seen.add(x))]

    @classmethod
    def first(cls, collection: Iterable[Any], attr: Optional[str] = None) -> Optional[Any]:
        """
        Gets the first element.

        WARNING: Tries to call ``next(x)``, progressing iterators.

        Args:
            collection: Any iterable
            attr: The name of the attribute that might be defined on the elements,
                or None to indicate the elements themselves should be used

        Returns:
            - The attribute of the first element if ``attr`` is defined on an element
            - None if the the sequence is empty
            - None if the sequence has no attribute ``attr``
        """
        try:
            # note: calling iter on an iterator creates a view only
            x = next(iter(collection))

            return x if attr is None else cls.look(x, attr)
        except StopIteration:
            return None

    @classmethod
    def iter_rowcol(cls, n_rows: int, n_cols: int) -> Generator[Tuple[int, int], None, None]:
        """
        An iterator over (row column) pairs for a row-first grid traversal.

        Example:
            .. code-block::
                it = CommonTools.iter_rowcol(5, 3)
                [next(it) for _ in range(5)]  # [(0,0),(0,1),(0,2),(1,0),(1,1)]
        """
        for i in range(n_rows * n_cols):
            yield i // n_cols, i % n_cols

    @classmethod
    def multidict(
        cls,

        sequence: Iterable[Z],

        key_attr: Union[str, Iterable[str], Callable[[Y], Z]],

        skip_none: bool = False,

    ) -> Mapping[Y, Sequence[Z]]:
        """
        Builds a mapping from keys to multiple values.
        Builds a mapping of some attribute in ``sequence`` to
        the containing elements of ``sequence``.

        Args:
            sequence: Any iterable
            key_attr: Usually string like 'attr1.attr2'; see `look`
            skip_none: If None, raises a `KeyError` if the key is missing for any item; otherwise, skips it

        """
        dct = defaultdict(lambda: [])
        for item in sequence:
            v = CommonTools.look(item, key_attr)

            if not skip_none and v is None:
                raise XKeyError(f"No {key_attr} in {item}", key=key_attr)
            if v is not None:
                dct[v].append(item)
        return dct

    @classmethod
    def mem_size(cls, obj) -> str:
        """
        Returns the size of the object in memory as a human-readable string.

        Args:
            obj: Any Python object

        Returns:
            A human-readable size with units
        """
        return nicesize(sys.getsizeof(obj))

    @classmethod
    def devnull(cls):
        """
        Yields a 'writer' that does nothing.

        Example:
            >>> with CommonTools.devnull() as devnull:
            >>>     devnull.write('hello')
        """
        yield DevNull()

    @classmethod
    def parse_bool(cls, s: str) -> bool:

        """
        Parses a 'true'/'false' string to a bool, ignoring case.

        Raises:
            ValueError: If neither true nor false
        """
        if isinstance(s, bool):
            return s
        if s.lower() == "false":
            return False
        if s.lower() == "true":
            return True
        raise XValueError(f"{s} is not true/false", value=s)

    @classmethod
    def parse_bool_flex(cls, s: str) -> bool:

        """
        Parses a 'true'/'false'/'yes'/'no'/... string to a bool, ignoring case.

        Allowed:
            - "true", "t", "yes", "y", "1", "+"
            - "false", "f", "no", "n", "0", "-"

        Raises:
            XValueError: If neither true nor false
        """
        mp = {

            **{v: True for v in {"true", "t", "yes", "y", "1", "+"}},
            **{v: False for v in {"false", "f", "no", "n", "0", "-"}},
        }
        v = mp.get(s.lower())

        if v is None:
            raise XValueError(f"{s.lower()} is not in {','.join(mp.keys())}", value=s)
        return v


__all__ = ["CommonTools"]


1			import sys
			0 ignored issues – show introduced 2021-01-25 05:25 UTC by Report Bug Copy Issue Report Missing module docstring Loading history...
2			from collections import defaultdict
3			from typing import (
4			Any,
5			Callable,
6			Generator,
7			Iterable,
8			Iterator,
9			Mapping,
10			Optional,
11			Sequence,
12			Tuple,
13			Type,
14			TypeVar,
15			Union,
16			)
17
18			import pandas as pd
			0 ignored issues – show introduced 2021-10-11 23:39 UTC by Report Bug Copy Issue Report Unable to import 'pandas' Loading history...
19
20			from pocketutils.core._internal import nicesize
			0 ignored issues – show Bug introduced 2021-10-28 02:10 UTC by Report Bug Copy Issue Report The name `core` does not seem to exist in module `pocketutils`. Loading history...
21			from pocketutils.core.exceptions import RefusingRequestError, XKeyError, XValueError
			0 ignored issues – show Bug introduced 2021-10-28 02:10 UTC by Report Bug Copy Issue Report The name `core` does not seem to exist in module `pocketutils`. Loading history...
22			from pocketutils.core.input_output import DevNull
			0 ignored issues – show Bug introduced 2021-10-28 02:10 UTC by Report Bug Copy Issue Report The name `core` does not seem to exist in module `pocketutils`. Loading history...
23			from pocketutils.tools.base_tools import BaseTools
24
25			Y = TypeVar("Y")
			0 ignored issues – show Coding Style Naming introduced 2021-01-25 05:25 UTC by Report Bug Copy Issue Report Class name "Y" doesn't conform to PascalCase naming style ('[^\\W\\da-z][^\\W_]+$' pattern) This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
26			T = TypeVar("T")
			0 ignored issues – show Coding Style Naming introduced 2021-01-25 05:25 UTC by Report Bug Copy Issue Report Class name "T" doesn't conform to PascalCase naming style ('[^\\W\\da-z][^\\W_]+$' pattern) This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
27			Z = TypeVar("Z")
			0 ignored issues – show Coding Style Naming introduced 2021-01-25 05:25 UTC by Report Bug Copy Issue Report Class name "Z" doesn't conform to PascalCase naming style ('[^\\W\\da-z][^\\W_]+$' pattern) This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
28			Q = TypeVar("Q")
			0 ignored issues – show Coding Style Naming introduced 2021-01-25 05:25 UTC by Report Bug Copy Issue Report Class name "Q" doesn't conform to PascalCase naming style ('[^\\W\\da-z][^\\W_]+$' pattern) This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
29
30
31			class CommonTools(BaseTools):

dmyersturnbull / pocketutils

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CommonTools.is_float() A

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