Turning loop of string inputs from Excel into Python lists
Question:
I have an Excel file with three columns (Prefix, Feature, Values). All three are strings in Excel, but I need to turn the ‘Values’ entry from a string into a list when Prefix and Column equal the loop values.
Data looks like this:
Prefix
Feature
Value
Prefix_1
Feature1
Value1,Value2,Value3
Prefix_1
Feature2
Value4,Value5
Prefix_1
Feature3
Value6,Value7,Value8,Value9
Prefix_2
Feature4
Value10
It loops through all prefixes, then through all features, and I want to return the values in a list.
parametric_values = str(filtered_input.loc[filtered_input.Feature==column,'Value']).split(',')
filtered_input is a dataframe that is filtered to only the relevant prefixes and column is the value from the loop.
I would have expected parametric_values to be ['Value1','Value2','Value3'] for the first loop, but it returned as ['0 Value1', 'Value2', 'Value3nName: Value', ' dtype: object']
I’m not sure why it returned a 0 to start with or the name and dtype object. What would I need to change with my code to get it to just return the values in the list?
Answers:
Use this instead:
filtered_input.loc[filtered_input.Feature==column,'Value'].str.split(',').squeeze()
Alert
From now on whenever you are trying to work with any pandas column values please avoid using the direct typecast ( bad practice ) and rather use astype() to change value type.
And Now For the solution to your problem please change your code as follows
parametric_values = filtered_input.loc[filtered_input.Feature==column,'Value'].astype(str).str.split(',').tolist()[0]
here,
filtered_input.loc[filtered_input.Feature==column,'Value'].astype(str).str.split(',')
This portion will only return a pandas series which is not the desired output so this series needs to be converted into a list. that’s why tolist() is added. But when you make a pandas series a list that also contains a list within it. Which will eventually generate something like this.
[[‘Value1’, ‘Value2’, ‘Value3’]]
which is also undesired output so lastly that [0] is added to get the actual list that you need.
Hope you find it helpful.
I have an Excel file with three columns (Prefix, Feature, Values). All three are strings in Excel, but I need to turn the ‘Values’ entry from a string into a list when Prefix and Column equal the loop values.
Data looks like this:
| Prefix | Feature | Value |
|---|---|---|
| Prefix_1 | Feature1 | Value1,Value2,Value3 |
| Prefix_1 | Feature2 | Value4,Value5 |
| Prefix_1 | Feature3 | Value6,Value7,Value8,Value9 |
| Prefix_2 | Feature4 | Value10 |
It loops through all prefixes, then through all features, and I want to return the values in a list.
parametric_values = str(filtered_input.loc[filtered_input.Feature==column,'Value']).split(',')
filtered_input is a dataframe that is filtered to only the relevant prefixes and column is the value from the loop.
I would have expected parametric_values to be ['Value1','Value2','Value3'] for the first loop, but it returned as ['0 Value1', 'Value2', 'Value3nName: Value', ' dtype: object']
I’m not sure why it returned a 0 to start with or the name and dtype object. What would I need to change with my code to get it to just return the values in the list?
Use this instead:
filtered_input.loc[filtered_input.Feature==column,'Value'].str.split(',').squeeze()
Alert
From now on whenever you are trying to work with any pandas column values please avoid using the direct typecast ( bad practice ) and rather use astype() to change value type.
And Now For the solution to your problem please change your code as follows
parametric_values = filtered_input.loc[filtered_input.Feature==column,'Value'].astype(str).str.split(',').tolist()[0]
here,
filtered_input.loc[filtered_input.Feature==column,'Value'].astype(str).str.split(',')
This portion will only return a pandas series which is not the desired output so this series needs to be converted into a list. that’s why tolist() is added. But when you make a pandas series a list that also contains a list within it. Which will eventually generate something like this.
[[‘Value1’, ‘Value2’, ‘Value3’]]
which is also undesired output so lastly that [0] is added to get the actual list that you need.
Hope you find it helpful.