I have been trying to use method chaining in Pandas however there are a few things related to how you reference a DataFrame or its columns that keep tripping me up. For example in the code below I have filtered the dataset and then want to create a new column that sums the columns remaining after the filter. …
Tag: dataframe
Add empty rows at the beginning of dataframe before export to xlsx
I have a pandas dataframe and I need to append 3 blank rows over the head of the columns before to export it to xlsx. I’m using this code based on this question: But it adds the rows at index 0 and I need the blank rows before the row with the column names in the xlsx. Is this possible
Creating a data frame from a list of lists with empty lists
Suppose we have some lists lst1 and lst2 and we want to create a data frame from them. So: When I try to create a data frame from these lists, it is empty: Is there any easy way to add the lst2 column even though it is empty? Answer There may be a more appropriate way to do this, but
Delete specific strings from pandas dataframe with operators chaining
I want to delete specific strings with regular expressions from the column Sorte which I don’t want to have in my dataframe file_df with the following code: But somehow when I execute this code these strings still are in the dataset and I can not figure out why. I wanted to chain this expression to not …
How to fillna in pandas dataframe based on pattern like in excel dragging?
I have dataframe which should be filled by understanding rows understanding like we do in excel. If its continious integer it fill by next number itself. Is there any function in python like this? output required: I tried df.interpolate(method=’krogh’) #it fill 1,2,3,4,5,6 but incorrect others. An…
add a suffix when col names are similar
I am merging two dataframes and both of them have a col called “man”. After the join, one col is called “man_x” and the second is called “man_y”. Is it possible to append the table name or any other string instead of x, y when column names are the same? After this, If I add…
Python Pandas compare two dataframe and keep only data that index appears in both dataframe
I have two dataframe, and would like to keep only row that both matches exactly on index (in this case datetime), and would like to return as two separate dataframe accordingly. Desired output: Answer Use align with inner join: *Note this will align both index and columns (which works for the provided sample)…
Python Data Frame summary
I have dataframe (df table below): Every user can post in any category. I have to calculate HOW MANY DISTINCT USERS has a post in category A and at the same time has posts in categories, B, C and D. Table like: User Category 1 A 1 B 33 B 33 C 33 D 54 A 54 B 87 A
Sum rows based on columns inside pandas dataframe
I am quite new to pandas, but I use python at a good level. I have a pandas dataframe which is organized as follows It is a fairly large dataframe (7 columns and ~600k rows). What I would like to do is: given a tuple containing values referring to the idbasin column (e.g. (1,2)), if the idrun value is the
How to make this code not to consume so much RAM memory?
I have these two function and when I run them my kernel dies so freaking quickly. What can I do to prevent it? It happens after appending about 10 files to the dataframe. Unfortunately json files are such big (approx. 150 MB per one, having dozens of them) and I have no idea how to join it together. EDIT: Due