Make compiler dependencies optional

README.md

@@ -39,13 +39,17 @@ This project is a reimplementation from the ground up focused on idiomatic moder
 
 ## Installation & Getting Started
 
-First, install the package:
+First, install the package. Note that the `[compiler]` feature flag tells it to install extra dependencies only needed by the `protoc` plugin:
 
 ```sh
+# Install both the library and compiler
+$ pip install betterproto[compiler]
+
+# Install just the library (to use the generated code output)
 $ pip install betterproto
 ```
 
-Now, given a proto file, e.g `example.proto`:
+Now, given you installed the compiler and have a proto file, e.g `example.proto`:
 
 ```protobuf
 syntax = "proto3";

betterproto/plugin.py

@@ -8,7 +8,13 @@ import sys
 import textwrap
 from typing import Any, List, Tuple
 
-import jinja2
+try:
+    import jinja2
+except ImportError:
+    print(
+        "Unable to import `jinja2`. Did you install the compiler feature with `pip install betterproto[compiler]`?"
+    )
+    raise SystemExit(1)
 
 from google.protobuf.compiler import plugin_pb2 as plugin
 from google.protobuf.descriptor_pb2 import (

setup.py

@@ -14,7 +14,9 @@ setup(
     packages=find_packages(
         exclude=["tests", "*.tests", "*.tests.*", "output", "output.*"]
     ),
-    package_data={"betterproto": ["py.typed", "templates"]},
-    install_requires=["grpclib", "protobuf"],
+    package_data={"betterproto": ["py.typed", "templates/template.py"]},
+    python_requires=">=3.7",
+    install_requires=["grpclib"],
+    extras_require={"compiler": ["jinja2", "protobuf"]},
     zip_safe=False,
 )