Why do I get "Pickle - EOFError: Ran out of input" reading an empty file?

Question

I am getting an interesting error while trying to use Unpickler.load(), here is the source code:

open(target, 'a').close()
scores = {};
with open(target, "rb") as file:
    unpickler = pickle.Unpickler(file);
    scores = unpickler.load();
    if not isinstance(scores, dict):
        scores = {};

Here is the traceback:

Traceback (most recent call last):
File "G:\python\pendu\user_test.py", line 3, in <module>:
    save_user_points("Magix", 30);
File "G:\python\pendu\user.py", line 22, in save_user_points:
    scores = unpickler.load();
EOFError: Ran out of input

The file I am trying to read is empty. How can I avoid getting this error, and get an empty variable instead?

Answer 1

Most of the answers here have dealt with how to mange EOFError exceptions, which is really handy if you're unsure about whether the pickled object is empty or not.

However, if you're surprised that the pickle file is empty, it could be because you opened the filename through 'wb' or some other mode that could have over-written the file.

for example:

filename = 'cd.pkl'
with open(filename, 'wb') as f:
    classification_dict = pickle.load(f)

This will over-write the pickled file. You might have done this by mistake before using:

...
open(filename, 'rb') as f:

And then got the EOFError because the previous block of code over-wrote the cd.pkl file.

When working in Jupyter, or in the console (Spyder) I usually write a wrapper over the reading/writing code, and call the wrapper subsequently. This avoids common read-write mistakes, and saves a bit of time if you're going to be reading the same file multiple times through your travails

Answer 2

I would check that the file is not empty first:

import os

scores = {} # scores is an empty dict already

if os.path.getsize(target) > 0:      
    with open(target, "rb") as f:
        unpickler = pickle.Unpickler(f)
        # if file is not empty scores will be equal
        # to the value unpickled
        scores = unpickler.load()

Also open(target, 'a').close() is doing nothing in your code and you don't need to use ;.

Answer 3

It is very likely that the pickled file is empty.

It is surprisingly easy to overwrite a pickle file if you're copying and pasting code.

For example the following writes a pickle file:

pickle.dump(df,open('df.p','wb'))

And if you copied this code to reopen it, but forgot to change 'wb' to 'rb' then you would overwrite the file:

df=pickle.load(open('df.p','wb'))

The correct syntax is

df=pickle.load(open('df.p','rb'))

Answer 4

As you see, that's actually a natural error ..

A typical construct for reading from an Unpickler object would be like this ..

try:
    data = unpickler.load()
except EOFError:
    data = list()  # or whatever you want

EOFError is simply raised, because it was reading an empty file, it just meant End of File ..

Answer 5

You can catch that exception and return whatever you want from there.

open(target, 'a').close()
scores = {};
try:
    with open(target, "rb") as file:
        unpickler = pickle.Unpickler(file);
        scores = unpickler.load();
        if not isinstance(scores, dict):
            scores = {};
except EOFError:
    return {}

Answer 6

if path.exists(Score_file):
      try : 
         with open(Score_file , "rb") as prev_Scr:

            return Unpickler(prev_Scr).load()

    except EOFError : 

        return dict() 

Answer 7

Had the same issue. It turns out when I was writing to my pickle file I had not used the file.close(). Inserted that line in and the error was no more.

Answer 8

I have encountered this error many times and it always occurs because after writing into the file, I didn't close it. If we don't close the file the content stays in the buffer and the file stays empty. To save the content into the file, either file should be closed or file_object should go out of scope.

That's why at the time of loading it's giving the ran out of input error because the file is empty. So you have two options :

1. file_object.close()
2. file_object.flush(): if you don't wanna close your file in between the program, you can use the flush() function as it will forcefully move the content from the buffer to the file.

Answer 9

This error comes when your pickle file is empty (0 Bytes). You need to check the size of your pickle file first. This was the scenario in my case. Hope this helps!

Answer 10

Note that the mode of opening files is 'a' or some other have alphabet 'a' will also make error because of the overwritting.

pointer = open('makeaafile.txt', 'ab+')
tes = pickle.load(pointer, encoding='utf-8')

Answer 11

temp_model = os.path.join(models_dir, train_type + '_' + part + '_' + str(pc))
# print(type(temp_model)) # <class 'str'>
filehandler = open(temp_model, "rb")
# print(type(filehandler)) # <class '_io.BufferedReader'>
try:
    pdm_temp = pickle.load(filehandler)
except UnicodeDecodeError:
    pdm_temp = pickle.load(filehandler, fix_imports=True, encoding="latin1")

Answer 12

from os.path import getsize as size
from pickle import *
if size(target)>0:
    with open(target,'rb') as f:
        scores={i:j for i,j in enumerate(load(f))}
else: scores={}

#line 1. we importing Function 'getsize' from Library 'OS' sublibrary 'path' and we rename it with command 'as' for shorter style of writing. Important is hier that we loading only one single Func that we need and not whole Library! line 2. Same Idea, but when we dont know wich modul we will use in code at the begining, we can import all library using a command '*'. line 3. Conditional Statement... if size of your file >0 ( means obj is not an empty). 'target' is variable that schould be a bit earlier predefined. just an Example : target=(r'd:\dir1\dir.2..\YourDataFile.bin') Line 4. 'With open(target) as file:' an open construction for any file, u dont need then to use file.close(). it helps to avoid some typical Errors such as "Run out of input" or Permissions rights. 'rb' mod means 'rea binary' that u can only read(load) the data from your binary file but u cant modify/rewrite it. Line5. List comprehension method in applying to a Dictionary.. line 6. Case your datafile is empty, it will not raise an any Error msg, but return just an empty dictionary.