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default python won't switch to homebew installation

I know this question has been asked - but none of the solutions there seem to be working. I recently found out that on Mac OS, the native installation of python isn't very good. So, I installed homebrew, and installed Python 2 through there. My path is as follows:
~ echo $PATH
/usr/local/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin
However, I still get the following:
~ which python
/usr/bin/python
~ which python2
/usr/local/bin/python2
It's also probably important to note that my ~/.bash_profile, ~/.profile and ~/.zshrc files are empty.
Somehow, I think I got pip to work with the python2 (homebrew) installation. Basically, I did pip install pandas and I get the following outputs for the two python interpreters:
~ python
Python 2.7.10 (default, Feb 7 2017, 00:08:15)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.34)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named pandas
That is, it doesn't appear with the default python installation. However, I also have the following:
~ python2
Python 2.7.14 (default, Sep 25 2017, 09:53:22)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.37)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas
>>>
So, pandas is imported in the python2 (homebrew) python, but not the standard one. How can I get it so that the default python is my homebrew python? I also read somewhere that brew link python would work, but when I do that I get
~ brew link python
Warning: Already linked: /usr/local/Cellar/python/2.7.14
To relink: brew unlink python && brew link python
I want to be able to just use python my_file.py and have it use the homebrew installation. (Not sure if it's related, but hopefully this would also allow Sublime to use the homebrew install when I hit command + B).
Sorry for the long post, new computer and I'm trying to get this all correct before I do any big projects and find out halfway through that things aren't working the way I need them to.
Thanks!

The macOS system Python is installed at /usr/bin/python. This is the only one called python on your path.
Homebrew doesn't create a link for python in /usr/local/bin. If you want one you can create it yourself:
ln -s /usr/local/bin/python2 /usr/local/bin/python
Alternatively, just update your shebang lines to specify python2 or python3, which is probably better anyway (explicit is better than implicit).

python-Can't import module in Pycharm while I can import the same module in terminal?

I installed essentia by
brew install essentia --HEAD
message:
Python modules have been installed and Homebrew's site-packages is not
in your Python sys.path, so you will not be able to import the modules
this formula installed. If you plan to develop with these modules,
please run:
mkdir -p /Users/yangyy/Library/Python/2.7/lib/python/site-packages
echo 'import site; site.addsitedir("/usr/local/lib/python2.7/site-packages")' >> /Users/yangyy/Library/Python/2.7/lib/python/site-packages/homebrew.pth
I did as the message instructed and installed essentia successfully.
The module can be imported in terminal:
Python 2.7.11 (default, Feb 23 2016, 00:59:46)
[GCC 4.2.1 Compatible Apple LLVM 6.1.0 (clang-602.0.53)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
-import essentia
-exit()
$ which python
/usr/local/bin/python
I use Pycharm as my IDE. I tried all the interpreter, but still can't import this module.
In python, I tried:
>>> import essentia
>>> reload(essentia)
<module 'essentia' from '/usr/local/lib/python2.7/site-packages/essentia/__init__.pyc'>

Pycharm wont take package dependencies instead it contains package you should initiate for your projects..
so, for that, You should go to
settings -> project Interpreter
then choose your project and check your packages are there then click,
apply <-button
that's it

Why I can not use an installed module for python?

I have installed a python library MySQLdb, and it works yesterday. But today when I tried to run it, it goes on as following:
czhao#opx790:~$ python
Python 2.7.7 |Anaconda 2.0.1 (64-bit)| (default, Jun 2 2014, 12:34:02)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://binstar.org
>>> import MySQLdb
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named MySQLdb
It is really strange, so I try to re-install it, but it seems I do have the library in my computer:
czhao#opx790:~$ sudo apt-get install python-mysqldb
[sudo] password for czhao:
Reading package lists... Done
Building dependency tree
Reading state information... Done
python-mysqldb is already the newest version.
The following packages were automatically installed and are no longer required:
libgooglepinyin0-dev linux-headers-3.2.0-27 linux-headers-3.2.0-41
linux-headers-3.2.0-37 linux-headers-3.2.0-43 linux-headers-3.2.0-61
patchutils linux-headers-3.2.0-37-generic linux-headers-3.2.0-27-generic
linux-headers-3.2.0-61-generic linux-headers-3.2.0-43-generic dpatch
linux-headers-3.2.0-41-generic
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 16 not upgraded.
I do not know why, I have the library but python keep tell me I do not have it.

You are using Anaconda Python, but the package installed with apt-get was installed for the system Python. These two different distributions have different library directories, so packages/modules installed with one are not available for the other.
To get around this, use the pip program that came with Anaconda and run sudo pip install MySQL-python.

Using twisted on OS X Mavericks

I am trying to use twisted on OS X Mavericks, but I get this error message when I try to import it.
christohersmbp2:~ christopherspears$ python
Python 2.7.6 (default, Mar 8 2014, 09:29:01)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import twisted
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named twisted
My guess is that I am receiving this error because I am not using the default Python. I am using a Python installed with brew. Ideally, I would want to install twisted into a virtual environment to play with, but the docs are seriously lacking in details. Apparently, a dmg exists for Mac OS X 10.5, which is not helpful for me. I can install from the tarball into the virtual environment, but I am not sure how to do this. Any hints?

If you're using virtualenv, it doesn't matter whether you are using the system python or not.
Simply pip install twisted in your virtualenv, like:
$ workon MyTwistedEnv
$ pip install twisted
Currently, due to a bug in Xcode that affects all projects which contain extension modules, you may need to spell this
$ CFLAGS= pip install twisted
instead; hopefully this will be fixed soon. It may not affect brew installed Pythons, however.

Python 2.7 cannot import PyQt4

I've upgraded to Python 2.7 from Python 2.6 on Ubuntu Maverick Meerkat (10.10) and I'm unable to import PyQt4.
austin#gerald:~$ python2.7
Python 2.7.0+ (r27:82500, Sep 15 2010, 18:04:55)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import PyQt4
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named PyQt4
I installed both Python 2.7 (python2.7) and PyQt4 (python-qt4) from the Ubuntu repositories. I installed PyQt a while back, but I installed Python 2.7 recently.
If I try Python 2.6 (since it's shipped with Ubuntu, the command is simply python), it works perfectly. Watch:
austin#gerald:~$ python
Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import PyQt4
I know what the problem is: the PyQt4 modules are accessible by Python 2.6 but not 2.7. My question is, how do I get Python 2.7 to find the PyQt4 module(s)? Help!
Note: sorry if this belongs in Super User, I was just programming when I encountered this problem.

As PyQt is not using setup.py it cannot be installed using pip or easy_install
Here you have a tutorial showing how to build and install PyQt for python2.7:
http://problemssol.blogspot.com/2010/12/compile-and-install-pyqt4-for-python27.html
Update:
For Ubuntu 12.04+ just use apt-get:
apt-get install python-qt4

Under Ubuntu system, you could install it via apt-get
apt-get install python-qt4

OSX 10.8.2 tested:
sudo pip install SIP
got IOError: [Errno 2] No such file or directory: '/tmp/pip-build/SIP/setup.py'
It's ok then:
cd /tmp/pip-build/SIP
sudo python configure.py
make
sudo make install
download PyQt from: http://sourceforge.net/projects/pyqt/files/PyQt4/PyQt-4.9.6/PyQt-mac-gpl-4.9.6.tar.gz
unzip it.
cd PyQt-mac-gpl-4.9.6
sudo python configure.py
make
it will take a while, after make then:
sudo make install
Enjoy it :)

You can download any version of PyQt4 here for any version of Python but since you asked for python 2.7, Here is the link for the download for python 2.7:
https://sourceforge.net/projects/pyqt/files/PyQt4/PyQt-4.11.4/

You should install PyQt4 in the Python 2.7 environment. To do this run
easy_install2.7 PyQt4
If easy_install is not installed you will need to first download and install it by running
python2.7 setup.py install

Please install SIP module first,this is python and c/c++ lib tools, and PyQt4 lib