Error while pip install -r requirement.txt

[Rakshasv18]

Collecting alembic==0.8.9 Downloading https://files.pythonhosted.org/packages/63/ca/c60ba17274b6737ff9ff1f89f0fbc7da93e05dd12bbdaae5099df8b60d38/alembic-0.8.9.tar.gz (977kB) |█▍ | 40kB 37kB/s eta 0:00:25ERROR: Exception: Traceback (most recent call last): File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/cli/base_command.py", line 153, in _main status = self.run(options, args) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/commands/install.py", line 382, in run resolver.resolve(requirement_set) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/legacy_resolve.py", line 201, in resolve self._resolve_one(requirement_set, req) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/legacy_resolve.py", line 365, in _resolve_one abstract_dist = self._get_abstract_dist_for(req_to_install) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/legacy_resolve.py", line 313, in _get_abstract_dist_for req, self.session, self.finder, self.require_hashes File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/operations/prepare.py", line 194, in prepare_linked_requirement progress_bar=self.progress_bar File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 465, in unpack_url progress_bar=progress_bar File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 316, in unpack_http_url progress_bar) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 551, in _download_http_url _download_url(resp, link, content_file, hashes, progress_bar) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 253, in _download_url hashes.check_against_chunks(downloaded_chunks) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/utils/hashes.py", line 80, in check_against_chunks for chunk in chunks: File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 223, in written_chunks for chunk in chunks: File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/utils/ui.py", line 160, in iter for x in it: File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_internal/download.py", line 212, in resp_read decode_content=False): File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_vendor/urllib3/response.py", line 564, in stream data = self.read(amt=amt, decode_content=decode_content) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_vendor/urllib3/response.py", line 529, in read raise IncompleteRead(self._fp_bytes_read, self.length_remaining) File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/contextlib.py", line 35, in exit self.gen.throw(type, value, traceback) File "/Library/Python/2.7/site-packages/pip-19.3.1-py2.7.egg/pip/_vendor/urllib3/response.py", line 430, in _error_catcher raise ReadTimeoutError(self._pool, None, "Read timed out.") ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=443): Read timed out.