get the number of images that per week per year loading from a json file in order to tabulate per week and year later on

gist: files_per_week_per_year.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
__author__ = "[José M. Beltrán](<[email protected]>)"
__credits__ = ["José M. Beltrán"]
__license__ = "GPL-3.0"

"""
The json file has the following scheme:

{"20020614":{"KEY1":{"KEY1.1":"path_to_file_01", ...},
                           
            :{"KEY2":{"KEY2.1":"path_to_file_01", ...}}} 
  ...,

  "20120414": {"KEY1":{"KEY1.1":"path_to_file_01", ...},
                           
            :{"KEY2":{"KEY2.1":"path_to_file_01", ...}}}
}

Basically I have a time series satellite images. 
Only one dataset per given date. But I want to tabulate
the number of images that I have per week per year.
So I created a json file that holds the filepaths of
each image available.

"""

import json
json_file = "filepathlist_per_date.json"


# Loading data
with open(json_file, 'rb') as fp:
    filepaths_dict = json.load(fp)
    
# Create a dictonary that holds the number of images per week per year
# My time series spans from 2002 till 2012 inclusive, so I need to add 
# 2012 + 1 to include the year 2012 in my dictionary.

week_per_year_counter = {k: {} for k in range(2002, 2012 + 1)}

for date_string in l2p_filepaths_dict.keys():
    # Get the week number using the function date_to_week_number (available here:
    # https://gist.github.com/geogradient/6210d5e85d7867b5f9e6#file-date_to_week_number-py
    
    week_number = date_to_week_number(date_string)
    current_year = int(date_string[:4])

    if week_number not in week_per_year_counter[current_year].keys():
        # datasets_per_week_per_year_counter
        week_per_year_counter[cyear][week_number] = 1
    else:
        week_per_year_counter[cyear][week_number] = week_per_year_counter[cyear][week_number] + 1

# Can also be used to group the files by week and year based on the date keys

year_dict = {k: {} for k in range(2002, 2012 + 1)}

for date_string in l2p_filepaths_dict.keys():
    week_number = date_to_week_number(date_string)
    current_year = int(date_string[:4])

    if week_number not in year_dict[current_year].keys():
        # Create a list to hold the date_string keys for the given keys in the year_dict                               
        year_dict[current_year][week_number] = [date_string]
    else:
        # Note that the list must be extended not appended!                               
        year_dict[current_year][week_number].extend([date_string])

    year_dict[current_year][week_number].sort() 

# using len(year_dict[current_year][week_number]) is possible to get the number of files
# per year and week_number, and then tabulate