Question

I am trying to write a python script that I could easily export to friends without dependency problems, but am not sure how to do so. Specifically, my script relies on code from BeautifulSoup, but rather than forcing friends to have to install BeautifulSoup, I would rather just package the src for BeautifulSoup into a Libraries/ folder in my project files and call to functions from there. However, I can no longer simply “import bs4.” What is the correct way of going about this?

Thanks!

Answer 1

A common approach is ship a requirements file with a project, specifying which version of which library is required. This file is (by convention) often named requirements.txt and looks something like this:

MyApp
BeautifulSoup==3.2.1
SomeOtherLib==0.9.4
YetAnother>=0.2

(The fictional file above says: I need exactly BeautifulSoup 3.2.1, SomeOtherLib 0.9.4 and any version of YetAnother greater or equal to 0.2).

Then the user of this project can simply take you library, (create a virtualenv) and run

$ pip install -r requirements.txt

which then will fetch all libraries and makes them available either system-wide of project-wide (if virtualenv is used). Here’s a random python project off github, having a requirements file:

• https://github.com/laoqiu/pypress
• https://github.com/laoqiu/pypress/blob/master/requirements.txt

The nice thing about this approach is that you’ll get your transitive dependencies resolved automatically. Also, if you use virtualenv, you’ll get a clean separation of your projects and avoid library version collisions.