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Is it possible to specify the search path for a module in a python script? If it is, how do I do that?

I have been coding in python for about 2 months, but I'm only familiar with basic object-oriented programming, so I do not really understand things like how searching for modules is implemented. (Basically I'm a noob.)
I pip installed a package called Opentrons Opentrons 2.5.2 and all its dependencies into the samefolder as a python script I'm currently writing. However when I tried to import the module below[1], I get an error saying that "Opentrons is not a module". Then, I tried shifting it into the python library because I found out the search path using the pprint module and it seems to work. I was wondering if I can specify the search path from the .py file itself instead of manually printing the search path and putting the file into the library that the script searches for. (Willing to put in images of the directories I put the opentrons package in if it helps.)
[1]
import sys
import pprint
pprint.pprint(search.path)
from opentrons import robot, containers, instruments
Edit: I realise that the fact that I am running all my scripts in a Spyder console located in a python 3.6 environment might be important.

You can try using the __import__ function, or importlib. This should allow you to specify the path.

Importing dependencies works in Pycahrm not Terminal?

I used below solution for importing dependencies.
I found this solution works if I run the code in Pycharm but not in Terminal.
The error message in Terminal is "cannot find graphics.primitive".
I'm using Mac and Python 3.5.
Why I see different behaviors from the Terminal and Pycharm?
How may I make the solution work for both?
http://chimera.labs.oreilly.com/books/1230000000393/ch10.html#_solution_169
Making a Hierarchical Package of Modules
Problem
You want to organize your code into a package consisting of a hierarchical collection of modules.
Solution
Making a package structure is simple. Just organize your code as you wish on the file-system and make sure that every directory defines an init.py file. For example:
graphics/
__init__.py
primitive/
__init__.py
line.py
fill.py
text.py
formats/
__init__.py
png.py
jpg.py
Once you have done this, you should be able to perform various import statements, such as the following:
import graphics.primitive.line
from graphics.primitive import line
import graphics.formats.jpg as jpg

You need to make sure that the graphics package is in the Python search path. PyCharm does this by extending sys.path as follows:
import sys
sys.path.extend(['/Users/hackworth/Development/graphics_parent_dir', '/Applications/PyCharm.app/Contents/helpers/pycharm', '/Applications/PyCharm.app/Contents/helpers/pydev'])
You can do the same in your code replacing /Users/hackworth/graphics_parent_dir with the appropriate path, or you can include the full path to graphics_parent_dir in the PYTHONPATH environment variable. See the Python documentation for details.
Another option would be to place the graphics package into a location the is searched by default on your system.

ImportError: No module named '...', unable add path to PYTHONPATH

This is what I'm trying to do.
But after that problem resolved, I had this error: ImportError: No module named 'multiply'. What I could figure out was that I had to add the location of my module to PYTHONPATH.
I couldn't find PYTHONPATH in System variables list, so I created one (as mentioned here), added all the paths including the one I needed, but it didn't solve the problem.
So, I re-installed all the features of Python, even the ones I didn't earlier. Everywhere I read solutions, there is only written set this like this or something similar but no-one says where they are defined or how they work.
Hence my question arises why can't I find variables like PYTHONPATH or PYTHONHOME in System variables while Python says they can be set or where are they defined?
Can anyone explain how do environment variables (mentioned in Python's documentation) work?
How can I solve my 'ImportError`?

The installer might not have set those automatically. You can set them yourself in the command prompt if you like:
SET variableName = value
Or, if you use PowerShell:
$env:variableName = value
If you don't want to use system commands at all, it can be done from within python with the os module:
import os
os.environ[variableName] = value
If they are already set, but you want to add something to it, the process is a little different. Let's suppose the path you are trying to add to PYTHONPATH is path.
Using the command prompt:
SET PYTHONPATH=%PYTHONPATH%;path
Python:
import os
os.environ['PYTHONPATH'] = os.environ['PYTHONPATH'] + ";path"
If you are correct and this is happening because the module is not on PYTHONPATH, this should add it onto the path and fir the problem.
If it doesn't fix the ImportError, then the environment variables are probably not the issue.
Links to learn more about environment variables:
http://www.digitalcitizen.life/simple-questions-what-are-environment-variables
https://en.wikipedia.org/wiki/Environment_variable
http://www.computerhope.com/jargon/e/envivari.htm
Hope this helps.

How to import module from current non-default directory

I'm using Python 2.7. I'm rather new to the python langauge. I have two python modules - "Trailcrest.py" and "Glyph.py", both in the same folder, but not in the Python27 folder.
I need to import "Trailcrest.py" into "Glyph.py", but I am getting the message that "no such module exists".
Additionally, whatever means I use to import the module needs to not be dependent on a solid-state path. This program is cross-platform, and the path can be changed depending on the user's preferences. However, these two modules will always be in the same folder together.
How do I do this?

If you have Trailcrest.py and Glyph.py in the same folder, importing one into the other is as simple as:
import Trailcrest
import Glyph
If this does not work, there seems to be something wrong with your Python setup. You might want to check what's in sys.path.
import sys
print sys.path

To elaborate a bit on Ferdinand Beyer's answer, sys.path is a list of file locations that the default module importer checks. Some, though not all installations of python will add the current directory or the directory of the __main__ module to the path. To make sure that the paths relative to a given module are importable in that module, do something like this:
import os.path, sys
sys.path.append(os.path.dirname(__file__))
But something like that shouldn't ever make it into a "production" product. Instead, use something like distutils to install the module's package into the python site-packages directory.

This can also be achieved using the environment variable PYTHONPATH which also influences Python's search path. This can be done in a shell script so that the Python files do not need to be altered. If you want it to import from the current working directory use the . notation in bash:
export PYTHONPATH=.
python python_prog.py

adding a subpackage from a different path

I have a python package called zypp. It is generated via swig and the rpm package (called python-zypp) puts it in:
rpm -ql python-zypp
/usr/lib64/python2.6/site-packages/_zypp.so
/usr/lib64/python2.6/site-packages/zypp.py
Now, I have a different project which provides an additional sets of APIs. Pure python. Plus some scripts.
The layout is:
bin/script1
python
python/zypp
python/zypp/plugins.py
python/zypp/__init__.py
plugins.py contains a Plugin class. I intended to put this in an rpm, and put it into
/usr/lib64/python2.6/site-packages/zypp/plugins.py
script1 uses this Plugin class. But as I test it running from git, I would like it to find the module from git too if it is not installed. So it has something like:
sys.path.append(os.path.join(os.path.dirname(os.path.abspath(__file__)), '../python'))
from zypp.plugins import Plugin
However, it seems that if python-zypp is installed on /usr/lib64/python2.6/site-packages/zypp.py, then script1 won't find the plugins submodule anymore. If I uninstall python-zypp, it does.
So my question is if it is possible to extend a module by adding submodules, being the submodules being located in a different load path. Or will they always clash?
An analogy would be, I have a module foo. And I provide foo.extras in a different load path (which may use foo indeed). The script won't find foo.extras if foo is found first in the system load path. If I only use the custom load path, the script may not find foo module if foo.extras uses it.
I have more experience with ruby, but in ruby I could have installed:
/usr/lib64/ruby/gems/1.8/gems/foo-1.0/lib/foo/*
And I could have in my script:
bin/script
lib/foo/extras/*
I could do in script:
$: << File.join(File.dirname(__FILE__), "../lib"
and then my script could
require foo
require foo/extras
No mater if foo/extras is installed on the system or in the custom load path. They don't clash.
The other way around, I found out that with PYTHONPATH the local zypp.plugins is found first. But then the installed zypp module is not found:
import zypp # works, but seems to import the local one
from zypp.plugins import Plugin # works, PYTHONPATH finds it first
repoinfo = zypp.RepoInfo() # does not work

If I understand your question correctly, you want to use the development version of that module instead of the installed module. Therefore, you can use
PYTHONPATH
From the Module Search Path documentation:
When a module named spam is imported, the interpreter searches for a file named spam.py in the current directory, and then in the list of directories specified by the environment variable PYTHONPATH. This has the same syntax as the shell variable PATH, that is, a list of directory names. When PYTHONPATH is not set, or when the file is not found there, the search continues in an installation-dependent default path; on Unix, this is usually .:/usr/local/lib/python.
So, if the GIT tree of the module directory was "/home/username/some/path", you would change the PYTHONPATH to "/home/username/some/path". Or if the PYTHONPATH variable is already in use, you would append ":/home/username/some/path" to it (note the colon separator). In order to make this permanent, add the line "PYTHONPATH=value" to the file "/etc/environment".
sys.path.insert
If you have a start script for your program, you could override the module search path using sys.path.insert(0, "somepath"). This is similar to the sys.path.append call you described but inserts the path into the beginning of the list.