[1055] Get the index of the “True” values in a Pandas Series

To get the index of the “True” values in a Pandas Series, you can use the index attribute along with boolean indexing. Here’s a simple way to do it:

1. Import Pandas:

   import pandas as pd

2. Create your Series:

   series = pd.Series([True, False, True, False, True])

3. Get the indices of “True” values:

   true_indices = series[series].index

4. Convert to a list (optional):

   true_indices_list = list(true_indices)

Here’s the complete code snippet:

import pandas as pd
 
# Create your Series
series = pd.Series([True, False, True, False, True])
 
# Get the indices of "True" values
true_indices = series[series].index
 
# Convert to a list (optional)
true_indices_list = list(true_indices)
 
print(true_indices_list)

This will output:

[0, 2, 4]

This method uses boolean indexing to filter the Series for “True” values and then retrieves their indices.

Would you like more details or help with another aspect of Pandas?

---

Sure, let’s break down the script step by step:

Script:

true_indices = series[series].index

Explanation:

1. series[series]:

   • This part uses boolean indexing. When you use a Series as an indexer for itself, it filters the Series based on the boolean values it contains.
   • For example, if series is:

     0     True
     1    False
     2     True
     3    False
     4     True
     dtype: bool

     Then series[series] will return only the elements where the value is True:

     0    True
     2    True
     4    True
     dtype: bool

2. .index:

   • The .index attribute of a Series returns the index labels of the Series.
   • Applying .index to the filtered Series (series[series]) will give you the indices of the True values.

Putting it all together:

• series[series] filters the Series to include only the True values.
• .index extracts the indices of these True values.

So, if series is:

0     True
1    False
2     True
3    False
4     True
dtype: bool

Then true_indices will be:

Int64Index([0, 2, 4], dtype='int64')

This means the indices of the True values are 0, 2, and 4.

Does this help clarify things? Would you like to dive deeper into any part of the explanation?