pandas select from Dataframe using startswith
This works (using Pandas 12 dev)
pandas
Pandas Extract Number from String
Given the following data frame:
Reconstruct a categorical variable from dummies in pandas
pd.get_dummies allows to convert a categorical variable into dummy variables. Besides the fact that it’s trivial to reconstruct the categorical variable, is there a preferred/quick way to do it?
Add Leading Zeros to Strings in Pandas Dataframe
I have a pandas data frame where the first 3 columns are strings:
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.
How to plot and annotate a grouped bar chart
I came across a tricky issue about the matplotlib in Python. I want to create a grouped bar chart with several codes, but the chart goes wrong. Could you please offer me some advice? The code is as follows.
add a string prefix to each value in a string column using Pandas
I would like to append a string to the start of each value in a said column of a pandas dataframe (elegantly).
I already figured out how to kind-of do this and I am currently using:
Pandas – Slice large dataframe into chunks
I have a large dataframe (>3MM rows) that I’m trying to pass through a function (the one below is largely simplified), and I keep getting a Memory Error message.
Convert unix time to readable date in pandas dataframe
I have a dataframe with unix times and prices in it. I want to convert the index column so that it shows in human readable dates.
Pandas DataFrame: replace all values in a column, based on condition
I have a simple DataFrame like the following: