Delete a column in a pandas' DataFrame if its sum is less than x

Question

I am trying to create a program that will delete a column in a Panda's dataFrame if the column's sum is less than 10.

I currently have the following solution, but I was curious if there is a more pythonic way to do this.

df = pandas.DataFrame(AllData)
sum = df.sum(axis=1)
badCols = list()
for index in range(len(sum)):
    if sum[index]  < 10:
        badCols.append(index)
df = df.drop(df.columns[badCols], axis=1)

In my approach, I create a list of column indexes that have sums less than 10, then I delete this list. Is there a better approach for doing this?

Answer 1

You can call sum to generate a Series that gives the sum of each column, then use this to generate a boolean mask against your column array and use this to filter the df. DF generation code borrowed from @Alexander:

In [2]:
df = pd.DataFrame({'a': [1, 10], 'b': [1, 1], 'c': [20, 30]})
df

Out[2]:
    a  b   c
0   1  1  20
1  10  1  30

In [3]:    
df.sum()

Out[3]:
a    11
b     2
c    50
dtype: int64

In [6]:
df[df.columns[df.sum()>10]]

Out[6]:
    a   c
0   1  20
1  10  30