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pandas

Python – rolling functions for GroupBy object

August 17, 2022 by Magenaut

I have a time series object grouped of the type <pandas.core.groupby.SeriesGroupBy object at 0x03F1A9F0>. grouped.sum() gives the desired result but I cannot get rolling_sum to work with the groupby object. Is there any way to apply rolling functions to groupby objects? For example:

Categories Python, Q&A Tags pandas, pandas-groupby, python, rolling-computation, rolling-sum Leave a comment

how do you filter pandas dataframes by multiple columns

August 17, 2022 by Magenaut

To filter a dataframe (df) by a single column, if we consider data with male and females we might:

Categories Python, Q&A Tags filter, pandas, python Leave a comment

Pandas: Subtracting two date columns and the result being an integer

August 17, 2022 by Magenaut

I have two columns in a Pandas data frame that are dates.

Categories Python, Q&A Tags datetime, int, numpy, pandas, python Leave a comment

Pandas: Cast column to string does not work

August 17, 2022 by Magenaut

I have a dataframe resultstatsDF

Categories Python, Q&A Tags pandas, python Leave a comment

Pandas GroupBy and select rows with the minimum value in a specific column

August 17, 2022 by Magenaut

I am grouping my dataset by column A and then would like to take the minimum value in column B and the corresponding value in column C.

Categories Python, Q&A Tags group-by, pandas, pandas-groupby, python Leave a comment

Parsing a JSON string which was loaded from a CSV using Pandas

August 17, 2022 by Magenaut

I am working with CSV files where several of the columns have a simple json object (several key value pairs) while other columns are normal. Here is an example:

Categories Python, Q&A Tags pandas, python Leave a comment

Pandas fill missing values in dataframe from another dataframe

August 17, 2022 by Magenaut

I cannot find a pandas function (which I had seen before) to substitute the NaN’s in a dataframe with values from another dataframe (assuming a common index which can be specified). Any help?

Categories Python, Q&A Tags fillna, pandas, python Leave a comment

Comparing previous row values in Pandas DataFrame

August 17, 2022 by Magenaut

import pandas as pd data={'col1':[1,3,3,1,2,3,2,2]} df=pd.DataFrame(data,columns=['col1']) print df col1 0 1 1 3 2 3 3 1 4 2 5 3 6 2 7 2 I have the following Pandas DataFrame and I want to create another column that compares the previous row of col1 to see if they are equal. What would be the … Read more

Categories Python, Q&A Tags boolean, numpy, pandas, python, shift Leave a comment

Most efficient way to forward-fill NaN values in numpy array

August 17, 2022 by Magenaut

Example Problem As a simple example, consider the numpy array arr as defined below: import numpy as np arr = np.array([[5, np.nan, np.nan, 7, 2], [3, np.nan, 1, 8, np.nan], [4, 9, 6, np.nan, np.nan]]) where arr looks like this in console output: array([[ 5., nan, nan, 7., 2.], [ 3., nan, 1., 8., nan], … Read more

Categories Python, Q&A Tags arrays, numpy, pandas, performance, python Leave a comment

Generating random dates within a given range in pandas

August 17, 2022 by Magenaut

This is a self-answered post. A common problem is to randomly generate dates between a given start and end date.

Categories Python, Q&A Tags datetime, pandas, python, random Leave a comment
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  1. michealSmith07 on Is there a way to dynamically refresh the less command?August 21, 2022

    That is a very nice post. I like this post.

  2. anonymous on Fix libwacom9 dependency issue when upgrade DebianJune 27, 2022

    saved my day!! Thanks for the help…

  3. sreedhar on Fix libwacom9 dependency issue when upgrade DebianMay 10, 2022

    Thanks its working

  4. saintnick on Fix libwacom9 dependency issue when upgrade DebianMay 10, 2022

    remove libwacom2 worked for me as well

  5. ranafoul on Fix libwacom9 dependency issue when upgrade DebianApril 22, 2022

    apt remove libwacom2 helped on kali 2022.01. gr8

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