TypeError：float（）参数必须是python的字符串或数字

Question

I am carrying out some calculation where i am dividing two values. The values i am dividing are two different list. So i know i can't be dividing a list with a list. I am not sure of how i can do this. Currently my code is as follows :

def files(currentd, previousd):

    with open(currentd, 'r') as current_data_file,\
            open(previousd, 'r') as pre_data_file:

        # load both data
        data_current = [json.loads(line) for line in current_data_file]
        data_previous = [json.loads(line) for line in pre_data_file]


        # store the previous names for  lookup
        pre_names = set([data["File Name"] for data in data_previous])
        pre_sizes = set([data["File Size"] for data in data_previous])
        cur_sizes = set(data["File Size"] for data in data_current)
        cur_names = set(data["File Name"] for data in data_current)



        # loop through all current data for matching names

        print("Looping through \n")

        for data in data_current:

           if data["File Name"] in pre_names :


               if pre_sizes is None and cur_sizes is None:
                  return "both missing"


               size_ratio = float(cur_sizes) / pre_sizes

Answer 1

You could store data from your files as dictionaries instead of sets and then look for files that are both in previous and current data to add their ratio to dict that we're going to return.

def files(currentd, previousd):
    # created example data
    data_current = [{'File Name': 'file1', 'File Size': 100}, {'File Name': 'file2', 'File Size': 600}]
    data_previous = [{'File Name': 'file2', 'File Size': 300}]

    # store the previous names for  lookup
    current = {i["File Name"]: i["File Size"] for i in data_current}
    previous = {i["File Name"]: i["File Size"] for i in data_previous}
    ratios = {}

    # loop through all current data for matching names
    for data in current.keys():
        if data in previous.keys():
            ratios[data] = float(current[data]) / previous[data]

    return ratios

print(files(0, 0)) # -> {'file2': 2.0}