record the location of a conditional entry in pandas

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Chapters
00:00 Record The Location Of A Conditional Entry In Pandas
00:39 Accepted Answer Score 3
01:15 Answer 2 Score 1
01:24 Thank you

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Full question
https://stackoverflow.com/questions/5240...

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https://meta.stackexchange.com/help/lice...

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Tags
#python #pandas

#avk47

ACCEPTED ANSWER

Score 3

Setup

df = pd.DataFrame(np.nan, range(54, 62), [*'ABCDEFGHIJ'])
df.at[56, 'G'] = 3
df.at[61, 'G'] = 2

`any` with `axis=1`

df.index[df.notna().any(1)]

Int64Index([56, 61], dtype='int64')

print(*df.index[df.notna().any(1)], sep='\n')

56
61

More Generally

`numpy.where`

i, j = np.where(df.notna())
print(*zip(df.index[i], df.columns[j]), sep='\n')

(56, 'G')
(61, 'G')

`stack`

By default, stack drops null values

print(*df.stack().index.values, sep='\n')

(56, 'G')
(61, 'G')

ANSWER 2

Score 1

Using notnull return Boolean , then sum and slice with the index

df.index[df.notnull().sum(1).nonzero()]
Out[646]: Int64Index([56, 61], dtype='int64')