I’m working through the “Python For Data Analysis” and I don’t understand a particular functionality. Adding two pandas series objects will automatically align the indexed data but if one object does not contain that index it is returned as NaN. For example from book:
I’m trying to read in a CSV file into a pandas dataframe and select a column, but keep getting a key error.
I have a DataFrame like :
Say I have the following Pandas Dataframe: df = pd.DataFrame({"a" : [1,2,3], "b" : [[1,2],[2,3,4],[5]]}) a b 0 1 [1, 2] 1 2 [2, 3, 4] 2 3 [5] How would I “unstack” the lists in the “b” column in order to transform it into the dataframe: a b 0 1 1 1 1 2 … Read more
I’m having trouble figuring out how to skip n rows in a csv file but keep the header which is the 1 row.
From what I understand about a left outer join, the resulting table should never have more rows than the left table…Please let me know if this is wrong…
I have two data frames with each having a different number of rows. Below is a couple rows from each data set
Assuming i have a DataFrame that looks like this:
I am using to_csv to write a Multiindex DataFrame to csv files. The csv file has one column that contains the multiindexes in tuples, like:
I have two dataframes in python. I want to update rows in first dataframe using matching values from another dataframe. Second dataframe serves as an override.