Clone this repository to start a new project or copy all of the files including the ‘.’ files into an existing project.

Add dependencies to ‘requirements.in’ the run ‘bazel run //:requirements.update’ to generate a versioned requirements file. After updating you will need to add the modified ‘requrements.txt’ file to git.

• bazel run <target>
• bazel build <target>
• bazle test <target>

Put python packages in the lib subdirectory. Create a directory that is the name of the package and add a BUILD file to that, then create another subdirectory of the same name. That is where the python files will go. This will keep the packages organized and have one BUILD file per package.

Example: package foo

lib
   /foo
       BUILD
       /foo
           bar.py

Usage:

from foo import bar

If you need to ‘import foo’ add an __init__.py file to the directory with the python files.

The BUILD file should include a single py_lib that looks like this:

load("@rules_python//python:defs.bzl", "py_library")

py_library(
    name = "lib_py",
    srcs = glob(["**/*.py"]),
    imports = ["."],
    visibility = ["//:__subpackages__"],
)

This will create a target //lib/package1:lib_py. The ‘imports’ argument will allow any users of the package to import using ‘import foo’ instead of import lib.foo.foo’.

If your package has any external requirements add them using using the ‘requirement’ function. See example in test.

Put executables in the bin directory. Create a subdirectory the same name as the executable. There should be one executable for each subdirectory. Add a BUILD file and make a py_bin target that is the same name as the directory. This will keep the executables organized.

Directory structure:

bin/
    hello/
        BUILD
        hello.py

BUILD file

load("@rules_python//python:defs.bzl", "py_binary")

py_binary(
    name = "hello",
    srcs = ["hello.py"],
    deps = [
	    "//lib/package1:lib_py",
    ],
)

This creates a target //bin/hello:hello which can be referred to in shorthand as //bin/hello or even bin/hello (if in the root of the workspace)

bazel run bin/hello
INFO: Analyzed target //bin/hello:hello (1 packages loaded, 2 targets configured).
INFO: Found 1 target...
Target //bin/hello:hello up-to-date:
  bazel-bin/bin/hello/hello
INFO: Elapsed time: 0.197s, Critical Path: 0.02s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action
INFO: Running command line: bazel-bin/bin/hello/hello
hello world!

Add tests to the test directory. An example test is included using the Ward testing framework as an external dependency and package1 as a dependency from this WORKSPACE.

load("@rules_python//python:defs.bzl", "py_test")
load("@pip_deps//:requirements.bzl", "requirement")

py_test(
    name = "test_package1",
    srcs = ["test_package1.py"],
    deps = [
        requirement("ward"),
        "//lib/package1:lib_py",
    ],
)

Run all tests pick specific tests to run.

bazel test //test:all
INFO: Analyzed target //test:test_package1 (0 packages loaded, 0 targets configured).
INFO: Found 1 test target...
Target //test:test_package1 up-to-date:
  bazel-bin/test/test_package1
INFO: Elapsed time: 1.994s, Critical Path: 1.88s
INFO: 2 processes: 2 darwin-sandbox.
INFO: Build completed successfully, 2 total actions
//test:test_package1                                                     PASSED in 1.1s

Executed 1 out of 1 test: 1 test passes.
There were tests whose specified size is too big. Use the --test_verbose_timeout_warnings command line option to see which ones these are.