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: pandas
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
Create calculated field within dataset using Python
I have a dataset, df, where I would like to create columns that display the output of a subtraction calculation: Data Desired Doing I am looking for a more elegant way that provides the desire output. Any suggestion is appreciated. Answer We can perform 2D subtraction with numpy: Benefit here is that, no matt…
Pandas: Dataframe itertuples boolean series groupby optimization
I’m new in python. I have data frame (DF) example: id type 1 A 1 B 2 C 2 B I would like to add a column example A_flag group by id. In the end I have data frame (DF): id type A_flag 1 A 1 1 B 1 2 C 0 2 B 0 I can do this in
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 …
write filename when iterating through dataframes
I am passing to a function several pandas df: df here will be a pandas dataframe. How can I assign the diferent parameters of *args to a string like above ‘/transformed/’+str(df)+’.table’,sep=’t’ ?? I want to have three files written to disk with the following path: Answer …
Pandas create multiindex from array and OrderedDict
I have a pandas dataframe like so: I have have an array having level1 column names and an OrderedDict having level0 column names and how many columns fall under them: col_names and col_layout_dict are being used in other part of the code too, so I don’t want to change them and also, since they are alrea…
Python Dash: Exclude option from one dropdown when chosing the same option in another dropdown
I am working on a Python Dash dashboard and have two dropdowns with the same options: enter image description here When I select an option in the first dropdown, how do I exclude the same option from the second dropdown? – So that I cannot choose the same material with both dropdowns. Where and how woul…
np.select pandas dataframe based on column of prefix and values
So I have two dataframes main_df, about 800 rows description category ABCD ONE XYZ THREE ABC QWE keyword_df, it is about 50 rows keyword category AB FIVE What I’m trying to achieve = main_df description category ABCD ONE XYZ THREE ABC FIVE QWE 0 conditions = [(main_df[‘Description’].str.star…