python_dictionaries
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initialize a dictionary
In [1]: d = {'sun': 1, 'mon': 2, 'tue': 3} d Out[1]: {'sun': 1, 'mon': 2, 'tue': 3}
dump dictionary to file
You can use pprint (stands for pretty print)
$ ipython Python 3.10.9 | packaged by conda-forge | (main, Jan 11 2023, 15:15:40) [MSC v.1916 64 bit (AMD64)] IPython 8.8.0 -- An enhanced Interactive Python. Type '?' for help. In [1]: import pprint cats = [{'name': 'Zophie', 'desc': 'chubby'}, {'name': 'Pooka', 'desc': 'fluffy'}] pprint.pformat(cats) Out[1]: "[{'desc': 'chubby', 'name': 'Zophie'}, {'desc': 'fluffy', 'name': 'Pooka'}]" In [2]: fileObj = open('myCats.py', 'w') fileObj.write('cats = ' + pprint.pformat(cats) + '\n') fileObj.close() In [3]: exit()
$ cat myCats.py cats = [{'desc': 'chubby', 'name': 'Zophie'}, {'desc': 'fluffy', 'name': 'Pooka'}]
$ ipython Python 3.10.9 | packaged by conda-forge | (main, Jan 11 2023, 15:15:40) [MSC v.1916 64 bit (AMD64)] IPython 8.8.0 -- An enhanced Interactive Python. Type '?' for help. In [1]: import myCats myCats.cats Out[1]: [{'desc': 'chubby', 'name': 'Zophie'}, {'desc': 'fluffy', 'name': 'Pooka'}] In [2]: myCats.cats[0] Out[2]: {'desc': 'chubby', 'name': 'Zophie'} In [3]: myCats.cats[0]['name'] Out[3]: 'Zophie' In [4]: exit()
Ref:-
- pprint is discussed in https://automatetheboringstuff.com/2e/chapter9/ → Saving Variables with the pprint.pformat() Function
merge python dictionaries
To merge two python dictionaries
def merge_two_dicts(x, y): ''' Given two dicts, merge them into a new dict as a shallow copy. For common keys, the values in y take precedence over values in x. ''' z = x.copy() z.update(y) return z
Sample usage:
>>> x = {'a': 1, 'b': 2} >>> y = {'b': 3, 'c': 4} >>> z = merge_two_dicts(x, y) >>> z {'a': 1, 'c': 4, 'b': 3}
To merge an undefined number of dicts
def merge_dicts(*dict_args): ''' Given any number of dicts, shallow copy and merge into a new dict, precedence goes to key value pairs in latter dicts. ''' result = {} for dictionary in dict_args: result.update(dictionary) return result
Given dicts a to g
z = merge_dicts(a, b, c, d, e, f, g)
will give a new dict z with all the key-value pairs. If same key exists in multiple dictionaries, the right most one will take precedence.
Ref:- http://stackoverflow.com/questions/38987/how-to-merge-two-python-dictionaries-in-a-single-expression
Convert a dictionary to a string
python_dictionaries.1677381564.txt.gz · Last modified: 2023/02/26 03:19 by raju