···

       
84
       
 
       
    """

     

       
85
       
 
       
    Tries to estimate how large a file the test data will be

     

       
86
       
 
       
    """

     

       
87
       
-
       
    max_string = float('-inf')

     

       
88
       
-
       
    min_string = float('inf')

     

       
89
       
-
       
    per_record_size = 0

     

       
90
       
-
       
    record_size_unit = "bytes"

     

       
91
       
 
       


     

       
92
       
-
       
    for station in weather_station_names:

     

       
93
       
-
       
        if len(station) > max_string:

     

       
94
       
-
       
            max_string = len(station)

     

       
95
       
-
       
        if len(station) < min_string:

     

       
96
       
-
       
            min_string = len(station)

     

       
97
       
-
       
        per_record_size = ((max_string + min_string * 2) + len(",-123.4")) / 2

     

       
98
       
 
       


     

       
99
       
-
       
    total_file_size = num_rows_to_create * per_record_size

     

       
100
       
-
       
    human_file_size = convert_bytes(total_file_size)

     

       
101
       
 
       


     

       
102
       
-
       
    return f"Estimated max file size is:  {human_file_size}.\nTrue size is probably much smaller (around half)."

     

       
103
       
 
       


     

       
104
       
 
       


     

       
105
       
 
       
def build_test_data(weather_station_names, num_rows_to_create):

     

···

       
84
       
 
       
    """

     

       
85
       
 
       
    Tries to estimate how large a file the test data will be

     

       
86
       
 
       
    """

     

       
87
       
+
       
    total_name_bytes = sum(len(s.encode("utf-8")) for s in weather_station_names)

     

       
88
       
+
       
    avg_name_bytes = total_name_bytes / float(len(weather_station_names))

     

       
0
       
 
       

     

       
0
       
 
       

     

       
89
       
 
       


     

       
90
       
+
       
    # avg_temp_bytes = sum(len(str(n / 10)) for n in range(-999, 1000)) / 1999

     

       
91
       
+
       
    avg_temp_bytes = 4.400200100050025

     

       
92
       
+
       


     

       
93
       
+
       
    # add 2 for separator and newline

     

       
94
       
+
       
    avg_line_length = avg_name_bytes + avg_temp_bytes + 2

     

       
0
       
 
       

     

       
95
       
 
       


     

       
96
       
+
       
    human_file_size = convert_bytes(num_rows_to_create * avg_line_length)

     

       
0
       
 
       

     

       
97
       
 
       


     

       
98
       
+
       
    return f"Estimated max file size is:  {human_file_size}."

     

       
99
       
 
       


     

       
100
       
 
       


     

       
101
       
 
       
def build_test_data(weather_station_names, num_rows_to_create):