Final answer:
To calculate the total number of study hours for a specific subject, iterate through the subject_log and hour_log lists, sum up the study hours for the desired subject, and return the total hours.
Step-by-step explanation:
To calculate the total number of study hours for a specific subject, you can use the subject_log and hour_log lists in Python. First, find the indices of the subject occurrences in subject_log using the index() method. Then, iterate through these indices and sum up the corresponding study hours from hour_log. Finally, return the total study hours. 
Here is an example:
def subject_study_hours(subject_log, hour_log, subject):
 total_hours = 0
 for i in range(len(subject_log)):
 if subject_log[i] == subject:
 total_hours += hour_log[i]
 return total_hours
If you call subject_study_hours(['comp', 'math', 'comp'], [1, 3, 2], 'comp'), it will return 3, which is the total number of study hours for the subject 'comp'.