Adding a Computed Column
~10 mincode completion
Write add_total(df) that adds a "total" column equal to price * quantity, and returns the DataFrame.
Examples
The new column holds price times quantity for each row
- Input
- add_total({"price": [2, 3], "quantity": [4, 5]})
- Output
- [8, 15]
A quantity of zero gives a total of zero, not a dropped row
- Input
- add_total({"price": [5, 5], "quantity": [0, 2]})
- Output
- [0, 10]
Hints
Hint 1
A list comprehension expresses this in one line.
Hint 2
A common slip here: added instead of multiplied.
Requirements
: a DataFrame with "price" and "quantity" columns
Return the DataFrame with the extra column.
Constraints
Standard library only, no imports required
Time limit: 200 ms, Memory: 64 MB
Where this shows up
~10 min
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Python
import pandas as pd
def add_total(df):
"""
Add a "total" column of price * quantity.
Args:
df: a DataFrame with "price" and "quantity" columns
Returns:
The DataFrame with the extra column.
"""
# YOUR CODE HERE
pass
def _run(df):
import pandas as pd
return add_total(pd.DataFrame(df))
def _totals(df):
import pandas as pd
return [float(v) for v in add_total(pd.DataFrame(df))["total"]]