I a importing a .csv file in python with pandas. Here is the file format from the .csv : here is how get it : Now when I print the file I get that : And so on… So I need help to read the file and split the values in columns, with the semi color character ;. Answer read_csv
Tag: pandas
Pandas: Group by calendar-week, then plot grouped barplots for the real datetime
EDIT I found a quite nice solution and posted it below as an answer. The result will look like this: Some example data you can generate for this problem: resulting in: I’d like to group by calendar-week and by value of col1. Like this: resulting in: Then I want a plot to be generated like this: That mea…
How to get output of pandas .plot(kind=’kde’)?
When I plot density distribution of my pandas Series I use Is it possible to get output values of this plot? If yes how to do this? I need the plotted values. Answer There are no output value from .plot(kind=’kde’), it returns a axes object. The raw values can be accessed by _x and _y method of th…
How do I create test and train samples from one dataframe with pandas?
I have a fairly large dataset in the form of a dataframe and I was wondering how I would be able to split the dataframe into two random samples (80% and 20%) for training and testing. Thanks! Answer I would just use numpy’s randn: And just to see this has worked:
pandas apply function that returns multiple values to rows in pandas dataframe
I have a dataframe with a timeindex and 3 columns containing the coordinates of a 3D vector: I would like to apply a transformation to each row that also returns a vector but if I do: I end up with a Pandas series whose elements are tuples. This is beacause apply will take the result of myfunc without unpacki…
Check if a value exists in pandas dataframe index
I am sure there is an obvious way to do this but cant think of anything slick right now. Basically instead of raising exception I would like to get True or False to see if a value exists in pandas df index. What I have working now is the following Answer This should do the trick
How to do/workaround a conditional join in python Pandas?
I am trying to calculate time-based aggregations in Pandas based on date values stored in a separate tables. The top of the first table table_a looks like this: Here is the code to create the table: The second table, table_b, looks like this: and the code to create it is: I want to be able to get the sum of
Add a sequential counter column on groups to a pandas dataframe
I feel like there is a better way than this: To achieve this: Is there a way to do it that avoids the callback? Answer use cumcount(), see docs here If you want orderings starting at 1
Merging two dataframes in pandas without column names (new to pandas)
Short explanation: If you have duplicate column names in your data, be sure to rename one column when you read the file. If you have NaN etc in your data, remove those. Then merge using correct answer below. Probably a pretty simple question. I have two datasets that I read in using pandas.read_csv(). My data…
How to write DataFrame to postgres table
There is DataFrame.to_sql method, but it works only for mysql, sqlite and oracle databases. I cant pass to this method postgres connection or sqlalchemy engine. Answer Starting from pandas 0.14 (released end of May 2014), postgresql is supported. The sql module now uses sqlalchemy to support different databas…