Source code for xclim.core.formatting

"""
Formatting Utilities for Indicators
===================================
"""

from __future__ import annotations

import datetime as dt
import itertools
import re
import string
import warnings
from collections.abc import Callable, Sequence
from fnmatch import fnmatch
from inspect import signature
from typing import Any

import xarray as xr
from boltons.funcutils import wraps

DEFAULT_FORMAT_PARAMS = {
    "tasmin_per_thresh": "{unknown}",
    "tasmin_per_window": "{unknown}",
    "tasmin_per_period": "{unknown}",
    "tas_per_thresh": "{unknown}",
    "tas_per_window": "{unknown}",
    "tas_per_period": "{unknown}",
    "tasmax_per_thresh": "{unknown}",
    "tasmax_per_window": "{unknown}",
    "tasmax_per_period": "{unknown}",
    "pr_per_thresh": "{unknown}",
    "pr_per_window": "{unknown}",
    "pr_per_period": "{unknown}",
}


[docs] class AttrFormatter(string.Formatter): """ A formatter for frequently used attribute values. Parameters ---------- mapping : dict of str, sequence of str A mapping from values to their possible variations. modifiers : sequence of str The list of modifiers. Must at least match the length of the longest value of `mapping`. Cannot include reserved modifier 'r'. Notes ----- See the doc of :py:meth:`format_field` for more details. """ def __init__( self, mapping: dict[str, Sequence[str]], modifiers: Sequence[str], ) -> None: """ Initialize the formatter. Parameters ---------- mapping : dict[str, Sequence[str]] A mapping from values to their possible variations. modifiers : Sequence[str] The list of modifiers. Must at least match the length of the longest value of `mapping`. Cannot include reserved modifier 'r'. """ super().__init__() if "r" in modifiers: raise ValueError("Modifier 'r' is reserved for default raw formatting.") self.modifiers = modifiers self.mapping = mapping
[docs] def format(self, format_string: str, /, *args: Any, **kwargs: Any) -> str: r""" Format a string. Parameters ---------- format_string : str The string to format. *args : Any Arguments to format. **kwargs : Any Keyword arguments to format. Returns ------- str The formatted string. """ for k, v in DEFAULT_FORMAT_PARAMS.items(): if k not in kwargs: kwargs.update({k: v}) return super().format(format_string, *args, **kwargs)
[docs] def format_field(self, value, format_spec: str) -> str: """ Format a value given a formatting spec. If `format_spec` is in this Formatter's modifiers, the corresponding variation of value is given. If `format_spec` is 'r' (raw), the value is returned unmodified. If `format_spec` is not specified but `value` is in the mapping, the first variation is returned. Parameters ---------- value : Any The value to format. format_spec : str The formatting spec. Returns ------- str The formatted value. Examples -------- Let's say the string "The dog is {adj1}, the goose is {adj2}" is to be translated to French and that we know that possible values of `adj` are `nice` and `evil`. In French, the genre of the noun changes the adjective (cat = chat is masculine, and goose = oie is feminine) so we initialize the formatter as: >>> fmt = AttrFormatter( ... { ... "nice": ["beau", "belle"], ... "evil": ["méchant", "méchante"], ... "smart": ["intelligent", "intelligente"], ... }, ... ["m", "f"], ... ) >>> fmt.format( ... "Le chien est {adj1:m}, l'oie est {adj2:f}, le gecko est {adj3:r}", ... adj1="nice", ... adj2="evil", ... adj3="smart", ... ) "Le chien est beau, l'oie est méchante, le gecko est smart" The base values may be given using unix shell-like patterns: >>> fmt = AttrFormatter( ... {"YS-*": ["annuel", "annuelle"], "MS": ["mensuel", "mensuelle"]}, ... ["m", "f"], ... ) >>> fmt.format( ... "La moyenne {freq:f} est faite sur un échantillon {src_timestep:m}", ... freq="YS-JUL", ... src_timestep="MS", ... ) 'La moyenne annuelle est faite sur un échantillon mensuel' """ baseval = self._match_value(value) if baseval is None: # Not something we know how to translate if format_spec in self.modifiers + ["r"]: # Woops, however a known format spec was asked warnings.warn(f"Requested formatting `{format_spec}` for unknown string `{value}`.") format_spec = "" return super().format_field(value, format_spec) # Thus, known value if not format_spec: # (None or '') No modifiers, return first return self.mapping[baseval][0] if format_spec == "r": # Raw modifier return super().format_field(value, "") if format_spec in self.modifiers: # Known modifier if len(self.mapping[baseval]) == 1: # But unmodifiable entry return self.mapping[baseval][0] # Known modifier, modifiable entry return self.mapping[baseval][self.modifiers.index(format_spec)] # Known value but unknown modifier, must be a built-in one, only works for the default val... return super().format_field(self.mapping[baseval][0], format_spec)
[docs] def _match_value(self, value): if isinstance(value, str): for mapval in self.mapping.keys(): if fnmatch(value, mapval): return mapval return None
# Tag mappings between keyword arguments and long-form text. default_formatter = AttrFormatter( { # Arguments to "freq" "D": ["daily", "days"], "YS": ["annual", "years"], "YS-*": ["annual", "years"], "YE": ["annual", "years"], "YE-*": ["annual", "years"], "MS": ["monthly", "months"], "ME": ["monthly", "months"], "QS-*": ["seasonal", "seasons"], # Arguments to "indexer" "DJF": ["winter"], "MAM": ["spring"], "JJA": ["summer"], "SON": ["fall"], "norm": ["Normal"], "m1": ["january"], "m2": ["february"], "m3": ["march"], "m4": ["april"], "m5": ["may"], "m6": ["june"], "m7": ["july"], "m8": ["august"], "m9": ["september"], "m10": ["october"], "m11": ["november"], "m12": ["december"], # Arguments to "statistic" (for example for generic.statistics) (annotation: Reducer) "integral": ["integrated", "integral"], "count": ["count"], "doymin": ["day of minimum"], "doymax": ["day of maximum"], "mean": ["average"], "max": ["maximal", "maximum"], "min": ["minimal", "minimum"], "sum": ["total", "sum"], "std": ["standard deviation"], "var": ["variance"], "absamp": ["absolute amplitude"], "relamp": ["relative amplitude"], # For when we are formatting indicator classes with empty options "<class 'inspect._empty'>": ["<empty>"], }, ["adj", "noun"], )
[docs] def merge_attributes( attribute: str, *inputs_list, # : xr.DataArray | xr.Dataset new_line: str = "\n", missing_str: str | None = None, **inputs_kws: xr.DataArray | xr.Dataset, ) -> str: r""" Merge attributes from several DataArrays or Datasets. If more than one input is given, its name (if available) is prepended as: "<input name> : <input attribute>". Parameters ---------- attribute : str The attribute to merge. *inputs_list : xr.DataArray or xr.Dataset The datasets or variables that were used to produce the new object. Inputs given that way will be prefixed by their `name` attribute if available. new_line : str The character to put between each instance of the attributes. Usually, in CF-conventions, the history attributes uses '\\n' while cell_methods uses ' '. missing_str : str A string that is printed if an input doesn't have the attribute. Defaults to None, in which case the input is simply skipped. **inputs_kws : xr.DataArray or xr.Dataset Mapping from names to the datasets or variables that were used to produce the new object. Inputs given that way will be prefixes by the passed name. Returns ------- str The new attribute made from the combination of the ones from all the inputs. """ inputs = [] for in_ds in inputs_list: inputs.append((getattr(in_ds, "name", None), in_ds)) inputs += list(inputs_kws.items()) merged_attr = "" for in_name, in_ds in inputs: if attribute in in_ds.attrs or missing_str is not None: if in_name is not None and len(inputs) > 1: merged_attr += f"{in_name}: " merged_attr += in_ds.attrs.get(attribute, "" if in_name is None else missing_str) merged_attr += new_line if len(new_line) > 0: return merged_attr[: -len(new_line)] # Remove the last added new_line return merged_attr
[docs] def update_history( hist_str: str, *inputs_list, # : xr.DataArray | xr.Dataset, new_name: str | None = None, **inputs_kws: xr.DataArray | xr.Dataset, ) -> str: r""" Return a history string with the timestamped message and the combination of the history of all inputs. The new history entry is formatted as "[<timestamp>] <new_name>: <hist_str> - xclim version: <xclim.__version__>." Parameters ---------- hist_str : str The string describing what has been done on the data. *inputs_list : xr.DataArray or xr.Dataset The datasets or variables that were used to produce the new object. Inputs given that way will be prefixed by their "name" attribute if available. new_name : str, optional The name of the newly created variable or dataset to prefix hist_msg. **inputs_kws : xr.DataArray or xr.Dataset Mapping from names to the datasets or variables that were used to produce the new object. Inputs given that way will be prefixes by the passed name. Returns ------- str The combine history of all inputs starting with `hist_str`. See Also -------- merge_attributes : Merge attributes from several DataArrays or Datasets. """ from xclim import ( # pylint: disable=cyclic-import,import-outside-toplevel __version__, ) merged_history = merge_attributes( "history", *inputs_list, new_line="\n", missing_str="", **inputs_kws, ) merged_history = ( f"[{dt.datetime.now():%Y-%m-%d %H:%M:%S}] {new_name or ''}: {hist_str} - xclim version: {__version__}\n" ) + merged_history return merged_history
[docs] def update_xclim_history(func: Callable) -> Callable: """ Decorator that auto-generates and fills the history attribute. The history is generated from the signature of the function and added to the first output. Because of a limitation of the `boltons` wrapper, all arguments passed to the wrapped function will be printed as keyword arguments. Parameters ---------- func : Callable The function to decorate. Returns ------- Callable The decorated function. """ @wraps(func) def _call_and_add_history(*args, **kwargs): """Call the function and then generate and add the history attr.""" outs = func(*args, **kwargs) if isinstance(outs, tuple): out = outs[0] else: out = outs if not isinstance(out, xr.DataArray | xr.Dataset): raise TypeError(f"Decorated `update_xclim_history` received a non-xarray output from {func.__name__}.") da_list = [arg for arg in args if isinstance(arg, xr.DataArray)] da_dict = {name: arg for name, arg in kwargs.items() if isinstance(arg, xr.DataArray)} # The wrapper hides how the user passed the arguments (positional or keyword) # Instead of having it all position, we have it all keyword-like for explicitness. bound_args = signature(func).bind(*args, **kwargs) attr = update_history( gen_call_string(func.__name__, **bound_args.arguments), *da_list, new_name=out.name if isinstance(out, xr.DataArray) else None, **da_dict, ) out.attrs["history"] = attr return outs return _call_and_add_history
[docs] def gen_call_string(funcname: str, *args: Any, **kwargs: Any) -> str: r""" Generate a signature string for use in the history attribute. DataArrays and Dataset are replaced with their name, while Nones, floats, ints and strings are printed directly. All other objects have their type printed between < >. Arguments given through positional arguments are printed positionnally and those given through keywords are printed prefixed by their name. Parameters ---------- funcname : str Name of the function. *args : Any Arguments given to the function. **kwargs : Any Keyword arguments given to the function. Returns ------- str The formatted string. Examples -------- >>> A = xr.DataArray([1], dims=("x",), name="A") >>> gen_call_string("func", A, b=2.0, c="3", d=[10] * 100) "func(A, b=2.0, c='3', d=<list>)" """ elements = [] chain = itertools.chain(zip([None] * len(args), args, strict=False), kwargs.items()) for name, val in chain: if isinstance(val, xr.DataArray): rep = val.name or "<array>" elif isinstance(val, int | float | str | bool) or val is None: rep = repr(val) else: rep = repr(val) if len(rep) > 50: rep = f"<{type(val).__name__}>" if name is not None: rep = f"{name}={rep}" elements.append(rep) return f"{funcname}({', '.join(elements)})"
[docs] def prefix_attrs(source: dict, keys: Sequence, prefix: str) -> dict: """ Rename some keys of a dictionary by adding a prefix. Parameters ---------- source : dict Source dictionary, for example data attributes. keys : sequence Names of keys to prefix. prefix : str Prefix to prepend to keys. Returns ------- dict Dictionary of attributes with some keys prefixed. """ out = {} for key, val in source.items(): if key in keys: out[f"{prefix}{key}"] = val else: out[key] = val return out
[docs] def unprefix_attrs(source: dict, keys: Sequence, prefix: str) -> dict: """ Remove prefix from keys in a dictionary. Parameters ---------- source : dict Source dictionary, for example data attributes. keys : sequence Names of original keys for which prefix should be removed. prefix : str Prefix to remove from keys. Returns ------- dict Dictionary of attributes whose keys were prefixed, with prefix removed. """ out = {} n = len(prefix) for key, val in source.items(): k = key[n:] if (k in keys) and key.startswith(prefix): out[k] = val elif key not in out: out[key] = val return out
[docs] def get_percentile_metadata(data: xr.DataArray, prefix: str) -> dict[str, str]: """ Get the metadata related to percentiles from the given DataArray as a dictionary. Parameters ---------- data : xr.DataArray Must be a percentile DataArray, this means the necessary metadata must be available in its attributes and coordinates. prefix : str The prefix to be used in the metadata key. Usually this takes the form of "tasmin_per" or equivalent. Returns ------- dict A mapping of the configuration used to compute these percentiles. """ # handle case where da was created with `quantile()` method if "quantile" in data.coords: percs = data.coords["quantile"].values * 100 elif "percentiles" in data.coords: percs = data.coords["percentiles"].values else: percs = "<unknown percentiles>" clim_bounds = data.attrs.get("climatology_bounds", "<unknown bounds>") return { f"{prefix}_thresh": percs, f"{prefix}_window": data.attrs.get("window", "<unknown window>"), f"{prefix}_period": clim_bounds, }
[docs] def capitalize_free_text(text, sep=". "): """ Ensure each sentence of the text begins with an uppercase letter. Parameters ---------- text : str A string. sep : str The separator indicating the end and the beginning of sentences, in addition to the first letter of the text. Returns ------- str The capitalized text. In opposition to :py:func:`str.capitalize()`, case of letters not at the beginning of a sentence is preserved. """ def _capitalize(m): return (m.groups()[0] or "") + m.groups()[-1].upper() patt = re.compile(f"(?:({re.escape(sep)})|(^))([a-z])") return re.sub(patt, _capitalize, text)