Python · Serialization: pickle, JSON & CSV

What's wrong with this pickle code? ``` with open("data.pkl", "w") as f: pickle.dump(obj, f) ```

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More in Serialization: pickle, JSON & CSV

What is the difference between pickle.dump / load and pickle.dumps / loads?

A web server unpickles a session blob that arrived from the client. A security reviewer flags it immediately. Why?

You pickle an object to a file, then a colleague tries to load it and gets an UnpicklingError. The data file is intact. What's the likely cause?

Which serializer should you reach for: arbitrary Python objects (custom classes, sets, tuples) to a local cache file, same Python program reads it back?

You dump three objects to one file with three pickle.dump calls. How do you read all three back?

What does this print? ``` import json s = json.dumps({1: "a", 2: "b"}) d = json.loads(s) print(list(d.keys())) ```

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