Coverage for stems/io/utils.py : 25%

""" IO utilities 

""" 

import datetime as dt 

import glob 

import os.path 

from pathlib import Path 

import numpy as np 

from ..compat import toolz 

def parse_paths(paths): 

""" Return a list of path(s) 

Parameters 

---------- 

paths : str or Sequence 

Either a string glob in the form "path/to/my/files/*.nc" or an explicit 

list of files to open. 

Returns 

------- 

list[Path] 

Paths determined from ``paths`` 

""" 

if isinstance(paths, (Path, str)): 

paths = os.path.expandvars(str(paths)) 

# Filename or glob, either way turn into list 

if '*' in str(paths): 

paths = glob.glob(paths) 

else: 

paths = [paths] 

elif isinstance(paths, (list, tuple)): 

paths = toolz.concat([parse_paths(p) for p in paths]) 

else: 

raise TypeError('`paths` must be a str, Path, or list/tuple') 

return list([Path(p) for p in paths]) 

def parse_filename_attrs(paths, index=None, sep=None): 

""" Parse filenames into an array of dates 

Parameters 

---------- 

paths : str or Sequence 

Glob style search pattern, or a list of filenames 

index : slice or int 

Either a ``slice`` used to index on the stem of the filenames 

in `paths`, or together with `sep` an `int` used to index on 

the filename stem split by `sep` (e.g., ``filename.split(sep)[index]``) 

sep : str, optional 

String field seperator 

Returns 

------- 

list[str] 

Attribute extracted from each filename path 

""" 

if index is None and sep is None: 

raise TypeError("Must provide either `index`, or `index` and `sep`") 

paths = parse_paths(paths) 

if not paths: 

raise IOError('No files to open') 

attrs = [] 

for path in paths: 

# Extract filename attributes 

if sep: 

string = path.stem.split(sep)[index] 

if isinstance(index, slice): 

# Asked for multiple components - rejoin into single str 

string = ''.join(string) 

else: 

string = path.stem[index] 

assert isinstance(string, str) 

attrs.append(string) 

return attrs 

def parse_filename_dates(paths, index=None, sep=None, date_format='%Y%m%d'): 

""" Parse filenames into an array of dates 

Parameters 

---------- 

paths : str or Sequence 

Glob style search pattern, or a list of filenames 

index : slice or int 

Either a ``slice`` used to index on the stem of the filenames 

in `paths`, or together with `sep` an `int` used to index on 

the filename stem split by `sep` (e.g., ``filename.split(sep)[index]``) 

sep : str, optional 

String field seperator 

date_format : str 

Date format used by :py:func:`datetime.datetime.strptime` 

Returns 

------- 

np.ndarray 

Array of datetime64 

See Also 

-------- 

""" 

attrs = parse_filename_attrs(paths, index=index, sep=sep) 

times = [np.datetime64(dt.datetime.strptime(attr, date_format)) 

for attr in attrs] 

return np.array(times)