How do you pass a dataframe column into a function in python?
So I have a large amount of columns within a pandas dataframe and I need to pass groups of them through a function. The function is large but I'll create an example below. I am not sure how to pass the reference of df.varName to the function without getting the issue of the variable not being defined. When I try a function such as: Show
I get the error that varX isn't defined. So I wrote the function where I would pass the whole phrase:
Where "varX = df.varX". This worked but isn't practical for a large number of variables because I would still have to manually update each varX and varT. So I tried creating a list of variables in the format df.varX and then using a for loop to pass the list of variables. The issue is python sees it as a string and not a reference. I looked at using functools.partial but was unsuccessful. Any ideas on how to write this in a simple format and be able to pass panda columns to a function? asked Feb 22, 2017 at 21:13
1 You may want to try this ?
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answered Feb 22, 2017 at 21:20
ShijoShijo 8,6752 gold badges17 silver badges30 bronze badges 1 View Discussion Improve Article Save Article View Discussion Improve Article Save Article In this article, we will learn different ways to apply a function to single or selected columns or rows in Dataframe. We will use Dataframe/series.apply() method to apply a function.
Method 1: Using
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: Example 2: For Row.
Output : Method 2: Using Example 1: For Column.
Output : Example 2: For Row.
Output : Method 3: Using
Output : Example 2: For Row.
Output : We can also apply a function to more than one column or row in the dataframe. Example 1: For Column
Output : Example 2: For Row.
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: How do you apply a function to a DataFrame column?Create a two-dimensional, size-mutable, potentially heterogeneous tabular data, df.. Print input DataFrame, df.. Override column x with lambda x: x*2 expression using apply() method.. Print the modified DataFrame.. Can we pass DataFrame to function?The apply() function, as its name states allows us to apply a function to each row of a dataframe. The apply() method passes into the the string_to_float() function a row from the df dataframe one by one. The row['value'] is simply the row of the df dataframe that is being passed onto the function.
How do I pass a specific column in pandas?Selecting columns based on their name
This is the most basic way to select a single column from a dataframe, just put the string name of the column in brackets. Returns a pandas series. Passing a list in the brackets lets you select multiple columns at the same time.
How do you use data frames in a function?DataFrame - apply() function. The apply() function is used to apply a function along an axis of the DataFrame. Objects passed to the function are Series objects whose index is either the DataFrame's index (axis=0) or the DataFrame's columns (axis=1).
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