Counting values greater than 0 in a given area (specific Rows * Columns) - Python, Excel, Pandas

Question

Based on the following data:

Participant	Condition	RT
1	1	0.10
1	1
1	2	0.48
2	1	1.2
2	2
2	2	0.58

What is the appropriate code to count the values which are greater than 0 based on the term:

Participant == 1 and Condition == 1

The answer Should be: N = 1 noting that an empty slot is not considered

Looking forward to your reply with gratitude, Avishai

Answer 1

Use a boolean mask and sum it:

N = sum((df['Participant'] == 1) & (df['Condition'] == 1) & (df['RT'].notna()))
print(N)

# Output
1

Details:

m1 = df['Participant'] == 1
m2 = df['Condition'] == 1
m3 = df['RT'].notna()
df[['m1', 'm2', 'm3']] = pd.concat([m1, m2, m3], axis=1)
print(df)

# Output
   Participant  Condition    RT     m1     m2     m3
0            1          1  0.10   True   True   True  # All True, N = 1
1            1          1   NaN   True   True  False
2            1          2  0.48   True  False   True
3            2          1  1.20  False   True   True
4            2          2   NaN  False  False  False
5            2          2  0.58  False  False   True