Eve: Building RESTful APIs with MongoDB and Flask Transcripts
Chapter: Setup and tools
Lecture: Installing Eve and its dependencies
Login or
purchase this course
to watch this video and the rest of the course contents.
0:01
Installing Eve is a simple task.
0:03
As with basically every other Python tool,
0:05
you really want to install it into a virtual environment.
0:08
A virtual environment is a Python environment
0:11
where the Python interpreter, libraries and scripts installed into it
0:15
are isolated from those installed in other virtual environments
0:18
and any libraries installed in a system Python,
0:21
like the one which is installed as part of your operating system.
0:25
So let's install Eve.
0:27
As you can see, I'm using a Mac here,
0:29
if you are on Windows, don't worry,
0:31
everything you see me doing during this course will also work on Windows
0:35
just make sure that you are using backslashes
0:37
whereas I'm typing forward slashes in the file paths,
0:43
folder names, stuff like that.
0:45
The first thing we want to do is make sure
0:47
that Python is actually installed on our system and ready to work.
0:50
So let's ask which Python 3, there it is, so we can use it.
0:56
If you wanted to use Python 2,
0:58
of course, we just have to go with Python.
1:03
We now want to create our vital environment
1:05
and within this virtual environment,
1:07
we will install Eve and all of its dependencies,
1:10
so Eve will be isolated from other Python installations in our system.
1:16
When it comes to virtual environments in Python
1:19
we are left with two options really,
1:21
one is called virtual env, you probably know about it already
1:25
because it's been around since forever,
1:27
it is very nice because it works equally well on Python 2 and Python 3,
1:32
so if you are working on Python 2, you probably want to use it.
1:36
You actually have to install it because it doesn't come with Python
1:40
but since we are working on Python 3,
1:42
we want to use the new method which comes built in with the Python itself
1:48
so we are going with Python 3 - m venv
1:53
and then it wants a path, virtual envs/eve-course,
1:59
so let's review this command here.
2:02
Python 3 is, of course, the interpreter,
2:05
- m is an option which is basically instructing Python
2:08
to execute the following module here as a script and then we have a path,
2:15
if the path doesn't exist on your system, it will be created for you.
2:19
As you can see, I'm using a root folder for all my virtual environments
2:23
and then I'm building an Eve course folder within the root folder.
2:28
Let's execute it— bam,
2:33
now let's take a look at our system,
2:36
as you can see, I have a new folder here virtual env,
2:39
and if I look at it there is my Eve course within it.
2:47
If we inspect the Eve course, we see that the number of folders on the file
2:51
we don't really care about what is being stored within this folder,
2:56
we just need to know that this is where all of our packages will be installed
3:02
and where the activation and the activation scripts
3:05
for our virtual environment are also stored.
3:08
How do we activate this virtual environment actually?
3:11
Well, I just use the source command
3:19
and then I go and use the activate script
3:24
as you can see, the prompt has changed
3:27
and it is telling me that now we are inside our virtual environment
3:31
and since we are inside a virtual environment
3:35
and every single virtual environment activated with Python
3:38
comes with the installation tools
3:41
we can already use pip
3:43
and ask for what's installed in our environment right now,
3:47
and of course, there is nothing because we just created this environment.
3:51
Now I can go and finally install Eve with pip install eve.
3:57
When I hit return here, it will go online, look up for Eve
4:01
and then install Eve itself and all of its dependencies.
4:09
There it goes.
4:11
As you can see it's collecting all the info
4:13
and then it is running all the setups,
4:16
scrapes for each of the dependencies,
4:20
and finally we get a very nice message here
4:22
which is telling us all the dependencies
4:25
with their versions which have been installed.
4:27
Now, if I try pip freeze again
4:32
I see that I have all of my dependencies ready to work
4:36
and in fact, if I run Python, I get Python 3.6.
4:41
I can for example import Eve— it works.
4:47
And how do I deactivate my virtual environment?
4:50
Well, it is very easy, I just need to use the deactivate command.
4:55
As you can see, the prompt has changed back again
4:58
to no virtual environment name
5:01
and in fact, if I try to use pip here, it doesn't even work
5:06
because it's not there, it only comes with virtual environment
5:11
or I have to install it on my system Python,
5:15
I can always go back to my
5:21
virtual environment and again, ready to work.