# Buggy code
def __init__(self, uri_path, min_part_size=WEBHDFS_MIN_PART_SIZE):
    """
    Parameters
    ----------
    min_part_size: int, optional
        For writing only.

    """
    self.uri_path = uri_path
    self._closed = False
    self.min_part_size = min_part_size
    # creating empty file first
    payload = {"op": "CREATE", "overwrite": True}
    init_response = requests.put(
        "http://" + self.uri_path, params=payload, allow_redirects=False
    )
    if not init_response.status_code == httplib.TEMPORARY_REDIRECT:
        raise WebHdfsException(
            str(init_response.status_code) + "\n" + init_response.content
        )
    uri = init_response.headers["location"]
    response = requests.put(
        uri, data="", headers={"content-type": "application/octet-stream"}
    )
    if not response.status_code == httplib.CREATED:
        raise WebHdfsException(str(response.status_code) + "\n" + response.content)
    self.lines = []
    self.parts = 0
    self.chunk_bytes = 0
    self.total_size = 0

    #
    # This member is part of the io.BufferedIOBase interface.
    #
    self.raw = None


# Traceback (TypeError)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-40-b63bd711d13c> in <module>
----> 1 smart_copy('./test_file.txt', 'webhdfs://XXXX@XXX.XXX.XXX.XXX:XXXXX/user/XXXX/smart_copy/test_file.txt')

<ipython-input-38-694f70cf0776> in smart_copy(source_file, sync_file)
3     '''
4     with open(source_file, 'rb') as source:
----> 5         with open(sync_file, 'wb') as sync:
6             for line in source:
7                 sync.write(line)

~/Github/tools/.venv/lib/python3.7/site-packages/smart_open/smart_open_lib.py in open(uri, mode, buffering, encoding, errors, newline, closefd, opener, ignore_ext, transport_params)
346     except KeyError:
347         binary_mode = mode
--> 348     binary, filename = _open_binary_stream(uri, binary_mode, transport_params)
349     if ignore_ext:
350         decompressed = binary

~/Github/tools/.venv/lib/python3.7/site-packages/smart_open/smart_open_lib.py in _open_binary_stream(uri, mode, transport_params)
560         elif parsed_uri.scheme == "webhdfs":
561             kw = _check_kwargs(smart_open_webhdfs.open, transport_params)
--> 562             return smart_open_webhdfs.open(parsed_uri.uri_path, mode, **kw), filename
563         elif parsed_uri.scheme.startswith('http'):
564             #

~/Github/tools/.venv/lib/python3.7/site-packages/smart_open/webhdfs.py in open(uri, mode, min_part_size)
40         return BufferedInputBase(uri)
41     elif mode == 'wb':
---> 42         return BufferedOutputBase(uri, min_part_size=min_part_size)
43     else:
44         raise NotImplementedError('webhdfs support for mode %r not implemented' % mode)

~/Github/tools/.venv/lib/python3.7/site-packages/smart_open/webhdfs.py in __init__(self, uri_path, min_part_size)
129                                      params=payload, allow_redirects=False)
130         if not init_response.status_code == httplib.TEMPORARY_REDIRECT:
--> 131             raise WebHdfsException(str(init_response.status_code) + "\n" + init_response.content)
132         uri = init_response.headers['location']
133         response = requests.put(uri, data="", headers={'content-type': 'application/octet-stream'})

TypeError: can only concatenate str (not "bytes") to str

# Fixed code
def __init__(self, uri, min_part_size=WEBHDFS_MIN_PART_SIZE):
    """
    Parameters
    ----------
    min_part_size: int, optional
        For writing only.

    """
    self._uri = uri
    self._closed = False
    self.min_part_size = min_part_size
    # creating empty file first
    payload = {"op": "CREATE", "overwrite": True}
    init_response = requests.put(self._uri, params=payload, allow_redirects=False)
    if not init_response.status_code == httplib.TEMPORARY_REDIRECT:
        raise WebHdfsException.from_response(init_response)
    uri = init_response.headers["location"]
    response = requests.put(
        uri, data="", headers={"content-type": "application/octet-stream"}
    )
    if not response.status_code == httplib.CREATED:
        raise WebHdfsException.from_response(response)
    self.lines = []
    self.parts = 0
    self.chunk_bytes = 0
    self.total_size = 0

    #
    # This member is part of the io.BufferedIOBase interface.
    #
    self.raw = None