CODEWITHSUNDEEP
pythonpickle
Michael
Michael

Reputation: 13914

Error Pickling in Python: io.UnsupportedOperation: read

I am trying to learn how to pickle and save an object in python. However, when I use the sample code below I get the following error: io.UnsupportedOperation: read which traces back to favorite_color = pickle.load(f_myfile). I cannot find a good explanation of this particular error. What am I doing wrong and how do I correct it?

import pickle  # or import cPickle as pickle

# Create dictionary, list, etc.
favorite_color = { "lion": "yellow", "kitty": "red" }

# Write to file
f_myfile = open('myfile.pickle', 'wb')
pickle.dump(favorite_color, f_myfile)
f_myfile.close()

# Read from file
f_myfile = open('myfile.pickle', 'wb')
favorite_color = pickle.load(f_myfile)  # variables come out in the order you put them in
f_myfile.close()

Upvotes: 40

Views: 70079

Answers (2)

Chandresh Thakur
Chandresh Thakur

Reputation: 31

You can also use:

f = open("myfile.dat", "wb+")

This is especially helpful when you must write and read the file but only want to open it once. Example:

    with open(file_path, "wb+") as file:
        # Write content from response to the file
        file.write(response.content)

        # Move the file pointer back to the beginning of the file and read
        file.seek(0)
        data = file.read(-1)

        # Calculate a hash or something

Upvotes: 3

Jay Choo
Jay Choo

Reputation: 1016

Change:

# Read from file 
f_myfile = open('myfile.pickle', 'wb')

to: 

f_myfile = open('myfile.pickle', 'rb')

and you can see the dict obj you've pickled.

Upvotes: 88

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