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Pandas Dedupe not working . Multiprocessing and Permission error


I was trying to clean up duplicates in an excel file using dedupe. The code worked fine at first and the code itself is simple. But whenever I run the code I get the below error. The code works fine if I delete all the temp files, restart pycharm or restart my computer and it won't run for the second time.

The data file is a csv file with a list of random similar name in column A with header as 'Name'. Please help tp resolve. Thank you. Code

import pandas as pd
import pandas_dedupe
#loading data
df = pd.read_csv('duplicate.csv')
#deduplication process
df_final = pandas_dedupe.dedupe_dataframe(df,['Name'])
#save to csv
df_final.to_csv('cleansed_output.csv')

Getting error below

C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\pandas_dedupe\utility_functions.py:17: FutureWarning: The default value of regex will change from True to False in a future version.
df[i] = df[i].str.replace('[^\w\s\.\-\(\)\,\:\/\\\\]','')
Reading from dedupe_dataframe_learned_settings
Clustering...
Traceback (most recent call last):
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\dedupe\api.py", line 103, in score
    matches = core.scoreDuplicates(pairs,
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\dedupe\core.py", line 244, in scoreDuplicates
    process.start()
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\process.py", line 121, in start
    self._popen = self._Popen(self)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\context.py", line 224, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\context.py", line 327, in _Popen
    return Popen(process_obj)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\popen_spawn_win32.py", line 45, in __init__
    prep_data = spawn.get_preparation_data(process_obj._name)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 154, in get_preparation_data
    _check_not_importing_main()
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 134, in _check_not_importing_main
    raise RuntimeError('''
RuntimeError: 
        An attempt has been made to start a new process before the
        current process has finished its bootstrapping phase.

        This probably means that you are not using fork to start your
        child processes and you have forgotten to use the proper idiom
        in the main module:

            if __name__ == '__main__':
                freeze_support()
                ...

        The "freeze_support()" line can be omitted if the program
        is not going to be frozen to produce an executable.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 125, in _main
    prepare(preparation_data)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 236, in prepare
    _fixup_main_from_path(data['init_main_from_path'])
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\multiprocessing\spawn.py", line 287, in _fixup_main_from_path
    main_content = runpy.run_path(main_path,
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 265, in run_path
    return _run_module_code(code, init_globals, run_name,
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 97, in _run_module_code
    _run_code(code, mod_globals, init_globals,
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\Username\PycharmProjects\Duplicate\main.py", line 10, in <module>
    df_final = pandas_dedupe.dedupe_dataframe(df,['Name'])
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\pandas_dedupe\dedupe_dataframe.py", line 249, in dedupe_dataframe
    clustered_df = _cluster(deduper, data_d, threshold, canonicalize)
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\pandas_dedupe\dedupe_dataframe.py", line 143, in _cluster
    clustered_dupes = deduper.partition(data, threshold)
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\dedupe\api.py", line 170, in partition
    pair_scores = self.score(pairs)
  File "C:\Users\Username\AppData\Roaming\Python\Python38\site-packages\dedupe\api.py", line 108, in score
    raise RuntimeError('''
RuntimeError: 
                You need to either turn off multiprocessing or protect
                the calls to the Dedupe methods with a
                `if __name__ == '__main__'` in your main module, see
                https://docs.python.org/3/library/multiprocessing.html#the-spawn-and-forkserver-start-methods
Traceback (most recent call last):
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 616, in _rmtree_unsafe
    os.unlink(fullname)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\USERNAME~1.KAB\\AppData\\Local\\Temp\\tmpp9123_pc\\blocks.db'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\tempfile.py", line 802, in onerror
    _os.unlink(path)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\USERNAME~1.KAB\\AppData\\Local\\Temp\\tmpp9123_pc\\blocks.db'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\weakref.py", line 642, in _exitfunc
    f()
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\weakref.py", line 566, in __call__
    return info.func(*info.args, **(info.kwargs or {}))
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\tempfile.py", line 817, in _cleanup
    cls._rmtree(name)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\tempfile.py", line 813, in _rmtree
    _shutil.rmtree(name, onerror=onerror)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 740, in rmtree
    return _rmtree_unsafe(path, onerror)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 618, in _rmtree_unsafe
    onerror(os.unlink, fullname, sys.exc_info())
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\tempfile.py", line 805, in onerror
    cls._rmtree(path)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\tempfile.py", line 813, in _rmtree
    _shutil.rmtree(name, onerror=onerror)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 740, in rmtree
    return _rmtree_unsafe(path, onerror)
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 599, in _rmtree_unsafe
    onerror(os.scandir, path, sys.exc_info())
  File "C:\Users\Username\AppData\Local\Programs\Python\Python38\lib\shutil.py", line 596, in _rmtree_unsafe
    with os.scandir(path) as scandir_it:
NotADirectoryError: [WinError 267] The directory name is invalid: 'C:\\Users\\USERNAME~1.KAB\\AppData\\Local\\Temp\\tmpp9123_pc\\blocks.db'

Process finished with exit code -1




     

Solution

  • The answer is in the error:

    You need to either turn off multiprocessing or protect the calls to the Dedupe methods with a if __name__ == '__main__' in your main module

    Change your code to the following, and try again:

    import pandas as pd
    import pandas_dedupe
    
    if __name__ == "__main__":
        #loading data
        df = pd.read_csv('duplicate.csv')
        #deduplication process
        df_final = pandas_dedupe.dedupe_dataframe(df,['Name'])
        #save to csv
        df_final.to_csv('cleansed_output.csv')