I would like to groupby the data in interval of a hourly/daily/weekly and further group by certain other clauses. I was able to acheive groupby hourly/daily/weekly basis by using groupby_dynamic option provided by polars. How do we add a secondary non datetime groupby clause to the polars dataframe after usin…
Tag: python-polars
Polars: settings not to display ellipsis
Polars chops some text instead of showing all text like the following Link Name https://… name1 https://… name2 I want Polars to show all text of Link Col How can I do that? Answer You should change pl.Config() settings – pl.Config.set_fmt_str_lengths(n) (see doc) If you just want to check, …
How to perform split/merge/melt with Python and polars?
I have a data transformation problem where the original data consists of “blocks” of three rows of data, where the first row denotes a ‘parent’ and the two others are related children. A minimum working example looks like this: In reality, there are up to 15 Providers (so up to 30 colu…
Polars equivalent of pandas expression df.groupby[‘col1′,’col2’][‘col3’].sum().unstack()
How can i create an equivalent truth table in polars? Something like the below table into a truth table The efficiency of the code is important as the dataset is too large (for using it with apriori algorithm) The unstack function in polars is different, polars alterative for pd.crosstab would also work. Answ…
How to use a polars column with offset string to add to another date column
Suppose you have and you want to make a new column that adds the hour and min offsets to the date column. The only thing I saw was the dt.offset_by method. I made an extra column and then tried but that doesn’t work because dt.offset_by only takes a fixed string, not another column. What’s the bes…
python-polars horizontally stack dataframe columns
how to horizontally stack data frame columns. the code below shows two data frames, I want to stack col 2 from df2 with col 1 from df1. how can I do this? Answer
How to ignore NULL fields while concatenating strings from multiple columns in python polars?
I have a dataframe with person names with these fields – last, first and middle names, i’m trying to concatenating these fields to get a full_name column in a dataframe as below. Here is the output: Why I’m getting null in full_name after concatenating last, first and middle_names ? Here If …
How to roll up duplicate observation in Python polars?
I have a data frame as- Here I would like to find out duplicates considering last_name and firs_name columns and if any duplicates found their respective ssn needs to be rolled up with semicolon(;) if SSN are not different. if SSN are also same only one SSN needs to be present. the expected output as: Here si…
Add timedelta to a date column above weeks
How would I add 1 year to a column? I’ve tried using map and apply but I failed miserably. I also wonder why pl.date() accepts integers while it advertises that it only accepts str or pli.Expr. A small hack workaround is: but this won’t work for months or days. I can’t just add a number or I…
Python Polars Parse Date from Epoch
How does one convert a column of i64 epoch strings into dates in polars? I’ve got a column of i64 representing seconds since epoch and I’d like to parse them into polars native datetimes. Answer Polars’ Datetime is represented as unix epoch in either, nanoseconds, microseconds or millisecond…