"""
Calculate percentage level of index for regions
inside the Verenigde Nederlanden.
"""

REGIONS = [
    'Amsterdam',
    'Northern Netherlands',
    'Eastern Netherlands',
    'Western Netherlands',
    'Southern Netherlands',
]

def region_in_string(string):
    """Look for region in string"""
    for region in REGIONS:
        if region in string:
            return True
    return False


def calculate_index():
    """Calculate index bases on file"""
    with open('regions.txt', 'r') as file:
        line_nr = 0
        last_percentage = 11
        for line in file:
            line_nr += 1
            if region_in_string(line):
                percentage = 11 - 10 / 998 * line_nr
                diff_percentage = last_percentage - percentage
                last_percentage = percentage
                region = line.strip().split('\t')
                print('%40s %2s %6.2f %% %6.2f %%' % (
                    region[0],
                    region[1],
                    percentage,
                    diff_percentage
                ))


if __name__ == '__main__':
    calculate_index()