如何将文件的大小和名称放入字典

Question

I have 3 files size_1.py size_2.py size.py

My Code is below

import os
result = {}
for (dirname,dirs,files) in os.walk('.'):
    for filename in files:
        if filename.endswith('.py'):
            thefile = os.path.join(dirname,filename)
            size =  (os.path.getsize(thefile),thefile)
           # print (size)
            result[size[0]] = size[1]
print (result)

My output

{315: './size.py', 249: './size_1.py'}

My Desired Output

{315:['./size.py']
249 : ['size_1.py', './size_2.py']
}

Answer 1

You only put strings in the values of result dictionary. You should put lists of strings. To do so, I suggest you to use defaultdict class to define directly a dictionary with lists as values, which is more comfortable.
I may also suggest you some minor improvements in your code for readability, as follows:

import os
from collections import defaultdict

result = defaultdict(list)
for (dirname,dirs,files) in os.walk('.'):
   for filename in files:
        if filename.endswith('.py'):
            thefile = os.path.join(dirname,filename)
            size =  os.path.getsize(thefile)
            result[size].append(thefile)
print (result)

Answer 2

You can use a defaultdict of list to easily do this, just append values instead of assigning.

import os
from collections import defaultdict
result = defaultdict(list)
for (dirname,dirs,files) in os.walk('.'):
    for filename in files:
        if filename.endswith('.py'):
            thefile = os.path.join(dirname,filename)
            size =  (os.path.getsize(thefile),thefile)
           # print (size)
            result[size[0]].append(size[1])
print (result)

---

Alternatively, without using defaultdict:

import os
result = {}
for (dirname,dirs,files) in os.walk('.'):
    for filename in files:
        if filename.endswith('.py'):
            thefile = os.path.join(dirname,filename)
            size =  (os.path.getsize(thefile),thefile)
           # print (size)
            result.setdefault(size[0], []).append(size[1])
print (result)

Answer 3

You can just add an if check to see if the key (size) exists in dictionary already:

import os
result = {}
for (dirname,dirs,files) in os.walk('.'):
    for filename in files:
        if filename.endswith('.py'):
            thefile = os.path.join(dirname,filename)
            size =  (os.path.getsize(thefile),thefile)
           # print (size)
        if size[0] in result:
            result[size[0]].append(size[1])
        else:
            result[size[0]] = [size[1]]
print (result)