Keep selected column as DataFrame instead of Series

by

As @Jeff mentions there are a few ways to do this, but I recommend using loc/iloc to be more explicit (and raise errors early if you’re trying something ambiguous):

In [10]: df = pd.DataFrame([[1, 2], [3, 4]], columns=['A', 'B'])

In [11]: df
Out[11]:
   A  B
0  1  2
1  3  4

In [12]: df[['A']]

In [13]: df[[0]]

In [14]: df.loc[:, ['A']]

In [15]: df.iloc[:, [0]]

Out[12-15]:  # they all return the same thing:
   A
0  1
1  3

The latter two choices remove ambiguity in the case of integer column names (precisely why loc/iloc were created). For example:

In [16]: df = pd.DataFrame([[1, 2], [3, 4]], columns=['A', 0])

In [17]: df
Out[17]:
   A  0
0  1  2
1  3  4

In [18]: df[[0]]  # ambiguous
Out[18]:
   A
0  1
1  3

More Related Contents:

  1. Clustered Stacked Bar in Python Pandas [closed]
  2. How to add a new column to an existing DataFrame?
  3. Pandas: Adding new column to dataframe which is a copy of the index column
  4. Python Pandas – Find difference between two data frames
  5. Convert pandas timezone-aware DateTimeIndex to naive timestamp, but in certain timezone
  6. Pandas groupby cumulative sum
  7. Convert columns to string in Pandas
  8. Use pandas.shift() within a group
  9. What is the most efficient way of counting occurrences in pandas?
  10. Pandas interpolate within a groupby
  11. Efficiently replace values from a column to another column Pandas DataFrame
  12. Precision lost while using read_csv in pandas
  13. Python Pandas: How to read only first n rows of CSV files in?
  14. Pandas – replacing column values
  15. Convert pandas dataframe from wide to long
  16. add columns different length pandas
  17. Pandas get the age from a date (example: date of birth)
  18. Adding a ‘count’ column to the result of a groupby in pandas?
  19. How to create a grouped bar plot
  20. Putting many python pandas dataframes to one excel worksheet
  21. Remove Unnamed columns in pandas dataframe [duplicate]
  22. Find difference between two data frames
  23. Datetime conversion – How to extract the inferred format?
  24. Bar graph from dataframe groupby
  25. What are the differences between feather and parquet?
  26. Reading multiple JSON records into a Pandas dataframe
  27. Efficient way to add rows to dataframe
  28. Find names of top-n highest-value columns in each pandas dataframe row
  29. pandas group by and assign a group id then ungroup
  30. Creating multiple Excel worksheets using data from a pandas DataFrame

Leave a Comment