Soooo you got the IndexError: only integers, slices (`:`), ellipsis (`…`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices error. Let’s get that annoying message fixed.
My Computer Setup
- Python3
- macOS
For those Short On Time
You’re trying to access an element of a Pandas index like df.columns where df is a DataFrame by using a string most likely. i is the name of the column in the code chunk below not the row index. That was my mistake.
Recreating the Problem
1 2 3 4 5 6 7 | import pandas as pddf = pd.DataFrame()df['one'] = [1,2,3]df['two'] = [1,2,3]for i, dtype in df.dtypes.iteritems(): print(df.columns[i]) |
So the code listed above should fail. I was under the impression that i was the column number in question. Instead i is the name of the column. df.columns is an array so I’m doing [1,2,3,4][‘bleh’] which is why it’s throwing the IndexError: only integers, slices (:), ellipsis (...), numpy.newaxis (None) and integer or boolean arrays are valid indices error.
Corrected Code
1 2 3 4 5 6 7 8 9 | import pandas as pddf = pd.DataFrame()df['one'] = [1,2,3]df['two'] = [1,2,3]for i, dtype in df.dtypes.iteritems(): # The following line is what resolves the error and # achieves our directive print(i) |
Lesson from all this?
So what’s the lesson from our mishap? I think I got misdirected by a few examples online that used i instead of a more descriptive variable name. Ideally that variable name would have been columnName. I always associate i with an integer which was my mistake. Hope that helps and happy coding!
Interested in Python orchestration? Check out this Airflow setup article.