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  lt module gt       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

User · Answer

if path exists Score file         try             with open Score file    rb   as prev Scr               return Unpickler prev Scr  load        except EOFError             return dict

User · Answer

I would check that the file is not empty first   import os  scores        scores is an empty dict already  if os path getsize target   gt  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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

User · Answer

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

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

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