Utility functions for pandas time series data.

Currently, pdts_utils.py code includes;

chunk_sizer function:

• Takes a Pandas.Series() object, such as a column from a time series dataframe.
• It calculates number of NaN elements and valid elements in a given column.
• It also counts the number of continuous NaN or valid chunks in the series.
• Returns the chunk list where it records all chunks consecutively with their sizes
• [Optional] endtrim True removes the last chunk in the series and return it, in case the last of the series is NaN.

valid_chunk function:

• Takes a Pandas.Series() object, such as a column from a time series dataframe.
• Calculates number of valid elements in a given column
• Provides the length of the longest valid chunk
• Provides histogram of the valid chunk sizes
• Returns the chunk list of the valid chunk sizes in their order

nan_chunk function:

• This function mirrors valid_chunk function to the NaN chunks.

max_pickler function (added September 13,2023):

• This uses valid_chunk() and nan_chunk functions together.
• It returns the starting and ending locations of the longest continuous valid number chunk