Bump Black version (20.8b1) and use --target-version=py36

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
 - repo: https://github.com/ambv/black
-  rev: 19.10b0
+  rev: 20.8b1
   hooks:
   - id: black
-    args: [--target-version=py35]
+    args: [--target-version=py36]

repo2docker/buildpacks/conda/__init__.py

@@ -266,8 +266,7 @@ class CondaBuildPack(BaseImage):
         return assemble_files
 
     def get_env_scripts(self):
-        """Return series of build-steps specific to this source repository.
+        """Return series of build-steps specific to this source repository."""
-        """
         scripts = []
         environment_yml = self.binder_path("environment.yml")
         env_prefix = "${KERNEL_PYTHON_PREFIX}" if self.py2 else "${NB_PYTHON_PREFIX}"
@@ -340,6 +339,5 @@ class CondaBuildPack(BaseImage):
         return scripts
 
     def detect(self):
-        """Check if current repo should be built with the Conda BuildPack.
+        """Check if current repo should be built with the Conda BuildPack."""
-        """
         return os.path.exists(self.binder_path("environment.yml")) and super().detect()

repo2docker/buildpacks/nix/__init__.py

@@ -8,8 +8,7 @@ class NixBuildPack(BaseImage):
     """A nix Package Manager BuildPack"""
 
     def get_path(self):
-        """Return paths to be added to PATH environemnt variable
+        """Return paths to be added to PATH environemnt variable"""
-        """
         return super().get_path() + ["/home/${NB_USER}/.nix-profile/bin"]
 
     def get_env(self):
@@ -47,16 +46,14 @@ class NixBuildPack(BaseImage):
         ]
 
     def get_build_script_files(self):
-        """Dict of files to be copied to the container image for use in building
+        """Dict of files to be copied to the container image for use in building"""
-        """
         return {
             "nix/install-nix.bash": "/home/${NB_USER}/.local/bin/install-nix.bash",
             "nix/nix-shell-wrapper": "/usr/local/bin/nix-shell-wrapper",
         }
 
     def get_assemble_scripts(self):
-        """Return series of build-steps specific to this source repository.
+        """Return series of build-steps specific to this source repository."""
-        """
         return super().get_assemble_scripts() + [
             (
                 "${NB_USER}",

repo2docker/buildpacks/pipfile/__init__.py

@@ -93,8 +93,7 @@ class PipfileBuildPack(CondaBuildPack):
         return scripts
 
     def get_assemble_scripts(self):
-        """Return series of build-steps specific to this repository.
+        """Return series of build-steps specific to this repository."""
-        """
         # If we have either Pipfile.lock, Pipfile, or runtime.txt declare the
         # use of Python 2, Python 2.7 will be made available in the *kernel*
         # environment. The notebook servers environment on the other hand
@@ -168,8 +167,7 @@ class PipfileBuildPack(CondaBuildPack):
         return assemble_scripts
 
     def detect(self):
-        """Check if current repo should be built with the Pipfile buildpack.
+        """Check if current repo should be built with the Pipfile buildpack."""
-        """
         # first make sure python is not explicitly unwanted
         runtime_txt = self.binder_path("runtime.txt")
         if os.path.exists(runtime_txt):

repo2docker/buildpacks/python/__init__.py

@@ -132,8 +132,7 @@ class PythonBuildPack(CondaBuildPack):
         return assemble_scripts
 
     def detect(self):
-        """Check if current repo should be built with the Python buildpack.
+        """Check if current repo should be built with the Python buildpack."""
-        """
         requirements_txt = self.binder_path("requirements.txt")
         runtime_txt = self.binder_path("runtime.txt")
         setup_py = "setup.py"