I've already installed argparse successfully, but it doesn't show up on pip list.
C:\Python34>pip install argparse
Collecting argparse
Downloading argparse-1.4.0-py2.py3-none-any.whl
Installing collected packages: argparse
Successfully installed argparse-1.4.0
C:\Python34>pip install argparse
Requirement already satisfied (use --upgrade to upgrade): argparse in c:\python34\lib\site-packages
C:\Python34>pip list
Bottleneck (1.0.0)
chardet (2.3.0)
fuzzywuzzy (0.10.0)
nltk (3.1)
numexpr (2.6.0)
numpy (1.10.4)
pandas (0.18.1)
pip (8.1.2)
python-dateutil (2.5.3)
pytz (2016.4)
scipy (0.17.0)
setuptools (18.2)
six (1.10.0)
on Windows 10.