modelx v0.12.0 (11 Jan 2021)

This release introduces the following enhancement.

Enhancements

New interface for pandas DataFrame and Series

pandas DataFrame and Series objects referenced in Models and Spaces can now be written to and read from Excel or CSV text files.

New methods, Model.new_pandas and UserSpace.new_pandas are introduced. By calling either method, the user can create a PandasData object that associates a DataFrame/Series with a file path and file type (“excel” or “csv”), and assigns the PandasData object to a Reference.

For example, the script below creates a sample DataFrame df:

>>> import pandas as pd

>>> import numpy as np

>>> index = pd.date_range("20210101", periods=3)

>>> df = pd.DataFrame(np.random.randn(3, 3), index=index, columns=list("XYZ"))

>>> df
                   X         Y         Z
2021-01-01  0.184497  0.140037 -1.599499
2021-01-02 -1.029170  0.588080  0.081129
2021-01-03  0.028450 -0.490102  0.025208

The code below creates a PandasData object containing the DataFrame created above, and assigns it to a Reference named x in Model1.Space1:

>>> import modelx as mx

>>> space = mx.new_space()      # Creates Model1.Space1

>>> space.new_pandas("x", "Space1/df.xlsx", data=df, filetype="excel")

>>> space.x
<modelx.io.pandasio.PandasData at 0x15efa565548>

To get the DataFrame, call the PandasData object or access its value property:

>>> space.x()     # or space.value
                   X         Y         Z
2021-01-01  0.184497  0.140037 -1.599499
2021-01-02 -1.029170  0.588080  0.081129
2021-01-03  0.028450 -0.490102  0.025208

When the model is saved, the DataFrame is written to an Excel file named df.xlsx placed under the Space1 folder in model.

>>> model.write("model")    # `model` is the parent of `space`

When the model is read back by modelx.read_model() function, the DataFrame is read from the file:

>>> model2 = mx.read_model("model", name="Model2")

>>> model2.Space1.x()
                   X         Y         Z
2021-01-01  0.184497  0.140037 -1.599499
2021-01-02 -1.029170  0.588080  0.081129
2021-01-03  0.028450 -0.490102  0.025208