why should I make a copy of a data frame in pandas
When selecting a sub dataframe from a parent dataframe, I noticed that some programmers make a copy of the data frame using the .copy() method. For example,
pandas
Creating an empty Pandas DataFrame, then filling it?
I’m starting from the pandas DataFrame docs here: http://pandas.pydata.org/pandas-docs/stable/dsintro.html
Strings in a DataFrame, but dtype is object
Why does Pandas tell me that I have objects, although every item in the selected column is a string — even after explicit conversion.
Stacked Bar Chart with Centered Labels
I’m trying to “robustly” center the data labels in a stacked bar chart. A simple code example and the result are given below. As you can see, the data labels aren’t really centered in all rectangles. What am I missing?
Import CSV file as a pandas DataFrame
What’s the Python way to read in a CSV file into a pandas DataFrame (which I can then use for statistical operations, can have differently-typed columns, etc.)?
How to determine whether a Pandas Column contains a particular value
I am trying to determine whether there is an entry in a Pandas column that has a particular value. I tried to do this with if x in df['id']. I thought this was working, except when I fed it a value that I knew was not in the column 43 in df['id'] it still returned True. When I subset to a data frame only containing entries matching the missing id df[df['id'] == 43] there are, obviously, no entries in it. How to I determine if a column in a Pandas data frame contains a particular value and why doesn’t my current method work? (FYI, I have the same problem when I use the implementation in this answer to a similar question).
Change one value based on another value in pandas
I’m trying to reproduce my Stata code in Python, and I was pointed in the direction of Pandas. I am, however, having a hard time wrapping my head around how to process the data.
Pandas: sum DataFrame rows for given columns
I have the following DataFrame:
How to save a pandas DataFrame table as a png
I constructed a pandas dataframe of results. This data frame acts as a table. There are MultiIndexed columns and each row represents a name, ie index=['name1','name2',...] when creating the DataFrame. I would like to display this table and save it as a png (or any graphic format really). At the moment, the closest I can get is converting it to html, but I would like a png. It looks like similar questions have been asked such as How to save the Pandas dataframe/series data as a figure?
python pandas remove duplicate columns
What is the easiest way to remove duplicate columns from a dataframe?