"""
Input/output utilities for the zdm package.
This module provides helper functions for file I/O operations including
JSON file handling and grid data persistence.
Functions
---------
- `process_jfile`: Load a JSON file
- `savejson`: Save a Python object to JSON
- `save_grid`: Save grid data to compressed file
- `load_grid`: Load grid data from compressed file
"""
import os
import gzip
import json
import numpy as np
[docs]
def process_jfile(jfile: str):
"""Load up a JSON file
Args:
jfile (str): JSON file
Returns:
dict: JSON parsed
"""
with open(jfile, 'rt') as fh:
obj = json.load(fh)
return obj
[docs]
def savejson(filename, obj, overwrite=False, indent=None, easy_to_read=False,
**kwargs):
""" Save a python object to filename using the JSON encoder.
Parameters
----------
filename : str
obj : object
Frequently a dict
overwrite : bool, optional
indent : int, optional
Input to json.dump
easy_to_read : bool, optional
Another approach and obj must be a dict
kwargs : optional
Passed to json.dump
Returns
-------
"""
# Hide this here..
import io
if os.path.lexists(filename) and not overwrite:
raise IOError('%s exists' % filename)
if easy_to_read:
if not isinstance(obj, dict):
raise IOError("This approach requires obj to be a dict")
with io.open(filename, 'w', encoding='utf-8') as f:
f.write(json.dumps(obj, sort_keys=True, indent=4,
separators=(',', ': '), **kwargs))
else:
if filename.endswith('.gz'):
with gzip.open(filename, 'wt') as fh:
json.dump(obj, fh, indent=indent, **kwargs)
else:
with open(filename, 'wt') as fh:
json.dump(obj, fh, indent=indent, **kwargs)
######### misc function to load some data - do we ever use it? ##########
[docs]
def load_data(filename):
if filename.endswith('.npy'):
data=np.load(filename)
elif filename.endswith('.txt') or filename.endswith('.txt'):
# assume a simple text file with whitespace separator
data=np.loadtxt(filename)
else:
raise ValueError('unrecognised type on z-dm file ',filename,' cannot read data')
return data