Pickle not working

[dqii]

I'm trying to pickle a dataframe with to_pickle and read_pickle, and when reading I get this error

---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in try_read(path, encoding)
165 warnings.simplefilter("ignore", Warning)
--> 166 return read_wrapper(lambda f: pkl.load(f))
167 except Exception: # noqa: E722

~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in read_wrapper(func)
145 compression=compression,
--> 146 is_text=False)
147 try:

~/miniconda3/lib/python3.7/site-packages/pandas/io/common.py in _get_handle(path_or_buf, mode, encoding, compression, memory_map, is_text)
412 msg = 'Unrecognized compression type: {}'.format(compression)
--> 413 raise ValueError(msg)
414

ValueError: Unrecognized compression type: infer

When adding "compression=None" as an argument to both to_pickle and read_pickle, I get this error instead

TypeError Traceback (most recent call last)
~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in try_read(path, encoding)
165 warnings.simplefilter("ignore", Warning)
--> 166 return read_wrapper(lambda f: pkl.load(f))
167 except Exception: # noqa: E722

~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in read_wrapper(func)
147 try:
--> 148 return func(f)
149 finally:

~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in (f)
165 warnings.simplefilter("ignore", Warning)
--> 166 return read_wrapper(lambda f: pkl.load(f))
167 except Exception: # noqa: E722

TypeError: file must have 'read' and 'readline' attributes

During handling of the above exception, another exception occurred:

AttributeError Traceback (most recent call last)
~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in try_read(path, encoding)
172 return read_wrapper(
--> 173 lambda f: pc.load(f, encoding=encoding, compat=False))
174 # compat pickle

~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in read_wrapper(func)
147 try:
--> 148 return func(f)
149 finally:

~/miniconda3/lib/python3.7/site-packages/pandas/io/pickle.py in (f)
172 return read_wrapper(
--> 173 lambda f: pc.load(f, encoding=encoding, compat=False))
174 # compat pickle

~/miniconda3/lib/python3.7/site-packages/pandas/compat/pickle_compat.py in load(fh, encoding, compat, is_verbose)
219 try:
--> 220 fh.seek(0)
221 if encoding is not None:

~/miniconda3/lib/python3.7/site-packages/pandas/core/generic.py in getattr(self, name)
5066 return self[name]
-> 5067 return object.getattribute(self, name)
5068

AttributeError: 'DataFrame' object has no attribute 'seek'

Is this a bug?

[akhmerov]

Did you try finding a minimal reproducible example? AttributeError: 'DataFrame' object has no attribute 'seek' suggests that the bug is in your code.

[jorisvandenbossche]

That's in any case not the expected behaviour. Can you try to make a reproducible example? Where and how are you saving the pickle file? (passing a file path?)

[dqii]

After trying to replicate the error and failing, I realized that the error was that I was calling read_pickle with a dataframe as opposed to the file name, as you are supposed to do. I'm sorry about this.

In hindsight, the error AttributeError: 'DataFrame' object has no attribute 'seek' was a clear indication of this error. For the future, is it possible the first error message could be any clearer? Either way I should have realized this earlier.

Thank you both for having taken a look.

[jorisvandenbossche]

OK, no problem. Closing then.