逻辑测试所有值，而不是一个python

Question

So I have my function which essentially check if a specific filename exists in both sets of data. If it does , then it will carry out some calculations on the filesize and output on the terminal the results. Since I am passing one file name to test , it begins to go through each filename in my list until it finishes. I just want to test it for filename 'a.json' as a test. Then i can test in isolation 'b.json' and 'c.json'. The output i currently get is :

a.json
()
(1000, 1000)
ok
b.json
()
(1000, 1000)
ok
c.json
()
(1000, 1000)
ok

So the pseudocode will be :

For a.json in file_names
if a.json exists in jsonDatacurrFile
 if  a.json exist in both jsonDataprevFile and jsonDatacurrFile
  use compare function with the filesize from jsonDatacurrFile and jsonDataprevFile for a.json and output whatever condition it meets

So an example output would be :

a.json - ok

The files are as follows :

jsonDataprevFile is equal to :

{"File Name": "a.json", "File Size": 1000}
{"File Name": "b.json", "File Size": 1000}
{"File Name": "c.json", "File Size": 1000}

jsonDatacurrFile

{"File Name": "a.json", "File Size": 1000}
{"File Name": "b.json", "File Size": 1000}
{"File Name": "c.json", "File Size": 1000}    

My current logic is as follows :

def compare(previous,current):
  # temporary for debug
  print()
  print(previous,current)

  tolerance = 0.4

  if previous is None and current is None:
      return "both missing"

  if previous is None:
      return "new"

  if current is None:
      return "missing"

  size_ratio = float(current)/previous

  if size_ratio >= 1 + tolerance:
      return "not ok %d%% bigger" % round(((size_ratio - 1) * 100),0)

  if size_ratio <= 1 - tolerance:
      return "not ok %d%% smaller" % round(((1 - size_ratio) * 100),0)

  return "ok"



def readFileIntoDict(pathOfFile):
  fo = open(pathOfFile, "rw+")
  linesOfFiles = fo.readlines()
  dataInFile = {}
  for line in linesOfFiles:
      jsonD = json.loads(line)
      dataInFile[jsonD['File Name']] = jsonD['File Size']
  return dataInFile

  jsonDataprevFile = readFileIntoDict('dates/2018-01-01.json')
  jsonDatacurrFile = readFileIntoDict('dates/2018-01-02.json')


file_names = ['a.json', 'b.json', 'c.json']
for fileNames in file_names:
    if fileNames in jsonDatacurrFile:
        if jsonDataprevFile[fileNames] == jsonDatacurrFile[fileNames]:
         print fileNames
         print(compare(jsonDataprevFile.get('a.json') , jsonDatacurrFile.get('a.json')))

Answer 1

A couple of points to help out. You are probably getting weird answers now because in this line:

if jsonDataprevFile[fileNames] == jsonDatacurrFile[fileNames]:

you are comparing the value in the dictionary (size), not the names, so you are only proceeding into the 'if' block when both are same size. Additionally, you are using the literal name 'a.json' in your call to the compare where you should be using the fileName variable.

A cleaner way to do this if you have a particular set of names you are looking for is to use the dict.keys() method to get set of keys for each and use set intersection on them to get the common ones...

names_of_interest = {'a.file', 'b.file'}
names_in_both = json_file_a.keys() & json_file_b.keys()
# find names of interest that are in both files...
names = names_of_interest & names_in_both
# now you can just iterate through that set and go to work....
for name in names:
  compare(json_file_a[name], json_file_b[name])

Note that if you just want to work on all common names, you can dump the names of interest list and just work on the intersection of the key sets