I'm doing some data munging which would be quite a bit simpler if I could stick a bunch of dictionaries in an in-memory database, then run simply queries against it. For example, something ...

I use the following method a lot to append a single row to a dataframe. One thing I really like about it is that it allows you to append a simple dict object. For example: # Creating an empty dataf...

The openxlsx::write.xlsx function is overwriting spreadsheet instead of adding another tab. I tried do follow some orientations of Stackoverflow, but without sucess. dt.escrita <- format(Sys.t...

I have dataframe: subject A_target_word_gd A_target_word_fd B_target_word_gd B_target_word_fd subject_type 1 1 2 3 4 mild 2 11 12 13 14 moderate And I want to melt it to a dataframe that wi...

I need to stripe the white spaces from a CSV file that I read import csv aList=[] with open(self.filename, 'r') as f: reader = csv.reader(f, delimiter=',', quoting=csv.QUOTE_NONE) for row in r...

I'm surely missing something simple here. Trying to merge two dataframes in pandas that have mostly the same column names, but the right dataframe has some columns that the left doesn't have, and v...

I have a data frame that I want to sort by one column than the next, (using tidyverse if possible). I checked the below address but the solutions did not seem to work. Order a "mixed" ...

I need to convert dates into Excel serial numbers for a data munging script I am writing. By playing with dates in my OpenOffice Calc workbook, I was able to deduce that '1-Jan 1899 00:00:00' maps ...

I have a dataframe: df = col1 col2 col3 1 2 3 1 4 6 3 7 2 I want to edit df, such that when the value of col1 is smaller than 2 , take the value from col3. So I will get: new_df = col1 col2...

How to remove the variables in python to clear ram memory in python? R : a = 2 rm(a) Python: a = 2 How to clear the single variables or a group of variables?

I am new to Python and have worked my way through a few books on it. Everything is great, except visualizations. I really dislike matplotlib and Bokeh requires too heavy of a stack. The workflow I...

I need some help with a concise and first of all efficient formulation in pandas of the following operation: Given a data frame of the format id a b c d 1 0 -1 1 1 42 0 1 0 0 128 1 -1 0 1 Const...

I encountered this behaviour when doing basic data munging, like in this example: In [55]: import pandas as pd In [56]: import numpy as np In [57]: rng = pd.date_range('1/1/2000', periods=10, freq...

Nine years ago when I started to parsing HTML and free text with Perl I read the classic Data Munging with Perl. Does someone know if David is planning to update the book or if there are similar bo...