Convert a Pandas DataFrame to a dictionary Convert a Pandas DataFrame to a dictionary python python

Convert a Pandas DataFrame to a dictionary


The to_dict() method sets the column names as dictionary keys so you'll need to reshape your DataFrame slightly. Setting the 'ID' column as the index and then transposing the DataFrame is one way to achieve this.

to_dict() also accepts an 'orient' argument which you'll need in order to output a list of values for each column. Otherwise, a dictionary of the form {index: value} will be returned for each column.

These steps can be done with the following line:

>>> df.set_index('ID').T.to_dict('list'){'p': [1, 3, 2], 'q': [4, 3, 2], 'r': [4, 0, 9]}

In case a different dictionary format is needed, here are examples of the possible orient arguments. Consider the following simple DataFrame:

>>> df = pd.DataFrame({'a': ['red', 'yellow', 'blue'], 'b': [0.5, 0.25, 0.125]})>>> df        a      b0     red  0.5001  yellow  0.2502    blue  0.125

Then the options are as follows.

dict - the default: column names are keys, values are dictionaries of index:data pairs

>>> df.to_dict('dict'){'a': {0: 'red', 1: 'yellow', 2: 'blue'},  'b': {0: 0.5, 1: 0.25, 2: 0.125}}

list - keys are column names, values are lists of column data

>>> df.to_dict('list'){'a': ['red', 'yellow', 'blue'],  'b': [0.5, 0.25, 0.125]}

series - like 'list', but values are Series

>>> df.to_dict('series'){'a': 0       red      1    yellow      2      blue      Name: a, dtype: object,  'b': 0    0.500      1    0.250      2    0.125      Name: b, dtype: float64}

split - splits columns/data/index as keys with values being column names, data values by row and index labels respectively

>>> df.to_dict('split'){'columns': ['a', 'b'], 'data': [['red', 0.5], ['yellow', 0.25], ['blue', 0.125]], 'index': [0, 1, 2]}

records - each row becomes a dictionary where key is column name and value is the data in the cell

>>> df.to_dict('records')[{'a': 'red', 'b': 0.5},  {'a': 'yellow', 'b': 0.25},  {'a': 'blue', 'b': 0.125}]

index - like 'records', but a dictionary of dictionaries with keys as index labels (rather than a list)

>>> df.to_dict('index'){0: {'a': 'red', 'b': 0.5}, 1: {'a': 'yellow', 'b': 0.25}, 2: {'a': 'blue', 'b': 0.125}}


Should a dictionary like:

{'red': '0.500', 'yellow': '0.250', 'blue': '0.125'}

be required out of a dataframe like:

        a      b0     red  0.5001  yellow  0.2502    blue  0.125

simplest way would be to do:

dict(df.values)

working snippet below:

import pandas as pddf = pd.DataFrame({'a': ['red', 'yellow', 'blue'], 'b': [0.5, 0.25, 0.125]})dict(df.values)


Follow these steps:

Suppose your dataframe is as follows:

>>> df   A  B  C ID0  1  3  2  p1  4  3  2  q2  4  0  9  r

1. Use set_index to set ID columns as the dataframe index.

    df.set_index("ID", drop=True, inplace=True)

2. Use the orient=index parameter to have the index as dictionary keys.

    dictionary = df.to_dict(orient="index")

The results will be as follows:

    >>> dictionary    {'q': {'A': 4, 'B': 3, 'D': 2}, 'p': {'A': 1, 'B': 3, 'D': 2}, 'r': {'A': 4, 'B': 0, 'D': 9}}

3. If you need to have each sample as a list run the following code. Determine the column order

column_order= ["A", "B", "C"] #  Determine your preferred order of columnsd = {} #  Initialize the new dictionary as an empty dictionaryfor k in dictionary:    d[k] = [dictionary[k][column_name] for column_name in column_order]


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