Support Pipfiles

[ehmatthes]

Handling projects that use a Pipfile instead of requirements.txt shouldn't be too difficult. It should be a matter of:

• Detecting which kind of file is being used.
• Writing to the appropriate file.
• Writing in the correct format.

[ehmatthes]

• [x] Initial detection
  • [x] Detect if a project is using requirements.txt.
  • [x] Set USING_REQUIREMENTS_TXT.
  • [x] Detect if a project is using Pipfile.
  • [x] Set USING_PIPFILE.
  • [x] Put current code in block that checks USING_REQUIREMENTS_TXT.
• [x] Set up a small local project using Pipfile.
• [x] Write requirements for Pipfile in appropriate place.

[ehmatthes]

In modifying Pipfile, I can't just append new package names onto the end of the file. They need to go in the [packages] section. Awk should be able to do this:

$ cat Pipfile
[[source]]
url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"

[packages]
requests = "*"

[dev-packages]
$ DATA='[packages]\ndjango = "*"'
$ awk -v r="$DATA" '{gsub(/\[packages\]/,r)}1' Pipfile | xargs -0 echo > PipfileModified && mv PipfileModified Pipfile
$ cat Pipfile
[[source]]
url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"

[packages]
django = "*"
requests = "*"

[dev-packages]

I'm sure there's a cleaner way to do this without the temporary PipfileModified, but this should get things working.

[ehmatthes]

A simple project using Pipenv to manage dependencies deploys successfully.