pandas series to dictionary python

>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(, {0: 1, 1: 2, 2: 3, 3: 4})

Here is what the above code is Doing:
1. Create a Series object with four integers.
2. Convert the Series to a dictionary.
3. Convert the Series to an OrderedDict.
4. Convert the Series to a defaultdict.

The first two conversions are straightforward. The third conversion is interesting.

The OrderedDict class is a dictionary that preserves the order of keys.

The defaultdict class is a dictionary that creates a new value for a key if the key doesn’t exist.

The defaultdict class is useful for creating dictionaries of lists.

The to_dict() method has a few other options.

The orient option specifies the format of the dictionary.

The orient option can be ‘index’, ‘columns’, or ‘records’.

The ‘index’ option creates a dictionary with the index as the key and the values as the values.

The ‘columns’ option creates a dictionary with the columns as the keys and the values as the values.

The ‘records’ option creates a dictionary with the index as the key and the columns as the values.

The columns option is the default.

The to_dict() method also has a flat option.

The flat option specifies whether the dictionary should be one-dimensional or two-dimensional.

The flat option is False by default.

The to_dict() method also has a into option.

The into option specifies the type of the dictionary.

The into option can be a dictionary, an OrderedDict, or a defaultdict.

The to_dict() method also has a typ option.

The typ option specifies the type of the values in the dictionary.

The typ option can be ‘series’, ‘dict’, or ‘list’.

The typ option is ‘series’ by default.

The to_dict() method also has a nan_rep option.

The nan_rep option specifies the string representation of NaN values.

The nan_rep option is ‘NaN’ by default.

The to_dict() method also has a date_unit option.

The date_unit option specifies the unit of time for the values in the dictionary.

The date_unit option is ‘s’ by default.

The to_dict() method also has a date_format option.