Memory error while using pip install Matplotlib

I am using Python 2.7, If i try to install Matplotlib I am getting this error if i use "pip install matplotlib"

 Exception:
  Traceback (most recent call last):
    File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 232, in main
      status = self.run(options, args)
    File "/usr/local/lib/python2.7/dist-packages/pip/commands/install.py", line 339, in run
      requirement_set.prepare_files(finder)
    File "/usr/local/lib/python2.7/dist-packages/pip/req/req_set.py", line 355, in prepare_files
      do_download, session=self.session,
    File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 782, in unpack_url
      session,
    File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 667, in unpack_http_url
      from_path, content_type = _download_http_url(link, session, temp_dir)
    File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 843, in _download_http_url
      _download_url(resp, link, content_file)
    File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 615, in _download_url
      for chunk in progress_indicator(resp_read(4096), 4096):
    File "/usr/local/lib/python2.7/dist-packages/pip/utils/ui.py", line 46, in iter
      for x in it:
    File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 580, in resp_read
      decode_content=False):
    File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/packages/urllib3/response.py", line 256, in stream
      data = self.read(amt=amt, decode_content=decode_content)
    File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/requests/packages/urllib3/response.py", line 186, in read
      data = self._fp.read(amt)
    File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/cachecontrol/filewrapper.py", line 54, in read
      self.__callback(self.__buf.getvalue())
    File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/cachecontrol/controller.py", line 205, in cache_response
      self.serializer.dumps(request, response, body=body),
    File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/cachecontrol/serialize.py", line 81, in dumps
      ).encode("utf8"),
  MemoryError"

What might the problem be? I am using raspberry Pi 2 with a 16gb SD card. I still have 8gb data free but still getting this error. Kindly help

This error is coming up because, it seems, pip's caching mechanism is trying to read the entire file into memory before caching it… which poses a problem in a limited-memory environment, as matplotlib is ~50mb.

A simpler solution, until pip is patched to use a constant-space caching algorithm, is to run pip with --no-cache-dir to avoid the cache:

$ pip --no-cache-dir install matplotlib

It seems that you have insufficient RAM to build matplotlib from scratch. To overcome that, either turn on swap:

# create swap file of 512 MB
dd if=/dev/zero of=/swapfile bs=1024 count=524288
# modify permissions
chown root:root /swapfile
chmod 0600 /swapfile
# setup swap area
mkswap /swapfile
# turn swap on
swapon /swapfile

Or, if you have raspbian installed on your SD card, you can install matplotlib from the repository:

apt-get install python-matplotlib