Python videos

datamatrix.convert

Convert between DataMatrix objects and types of data structures (notably pandas.DataFrame).

function from_json(s)

Requires json_tricks

Creates a DataMatrix from a json string.

Arguments:

  • s -- A json string.
    • Type: str

Returns:

A DataMatrix.

  • Type: DataMatrix.

function from_pandas(df)

Converts a pandas DataFrame to a DataMatrix.

Example:

import pandas as pd
from datamatrix import convert

df = pd.DataFrame( {'col' : [1,2,3] } )
dm = convert.from_pandas(df)
print(dm)

Output:

+---+-----+
| # | col |
+---+-----+
| 0 |  1  |
| 1 |  2  |
| 2 |  3  |
+---+-----+

Arguments:

  • df -- No description
    • Type: DataFrame

Returns:

No description

  • Type: DataMatrix

function to_json(dm)

Requires json_tricks

Creates (serializes) a json string from a DataMatrix.

Arguments:

  • dm -- A DataMatrix to serialize.
    • Type: DataMatrix

Returns:

A json string.

  • Type: str

function to_pandas(obj)

Converts a DataMatrix to a pandas DataFrame, or a column to a Series.

Example:

from datamatrix import DataMatrix, convert

dm = DataMatrix(length=3)
dm.col = 1, 2, 3
df = convert.to_pandas(dm)
print(df)

Output:

   col
0    1
1    2
2    3

Arguments:

  • obj -- No description
    • Type: DataMatrix, BaseColumn

Returns:

No description

  • Type: DataFrame, Series

function wrap_pandas(fnc)

A decorator for pandas functions. It converts a DataMatrix to a DataFrame, passes it to a function, and then converts the returned DataFrame back to a DataMatrix.

Example:

import pandas as pd
from datamatrix import convert as cnv

pivot_table = cnv.wrap_pandas(pd.pivot_table)

Arguments:

  • fnc -- A function that takes a DataFrame as first argument and returns a DataFrame as sole return argument.
    • Type: callable

Returns:

A function takes a DataMatrix as first argument and returns a DataMatrix as sole return argument.