From 92213162c29aad1b336663df1862ca4b7b0eeb2c Mon Sep 17 00:00:00 2001
From: Manuel Barkhau <mbarkhau@gmail.com>
Date: Thu, 18 Mar 2021 18:40:13 +0000
Subject: [PATCH] lazy import pkg_resources for faster cli

---
 src/bumpver/cli.py     |  5 ++---
 src/bumpver/version.py | 11 ++++++++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/bumpver/cli.py b/src/bumpver/cli.py
index 9b0fa80..2c4a816 100755
--- a/src/bumpver/cli.py
+++ b/src/bumpver/cli.py
@@ -14,7 +14,6 @@ import subprocess as sp
 
 import click
 import colorama
-import pkg_resources
 
 from . import vcs
 from . import config
@@ -509,7 +508,7 @@ def _is_valid_version(raw_pattern: str, old_version: str, new_version: str) -> b
         logger.error(f"Invalid version '{new_version}' for pattern '{raw_pattern}'")
         return False
 
-    if pkg_resources.parse_version(new_version) <= pkg_resources.parse_version(old_version):
+    if version.parse_version(new_version) <= version.parse_version(old_version):
         logger.error("Invariant violated: New version must be greater than old version ")
         logger.error(f"  Failed Invariant: '{new_version}' > '{old_version}'")
         return False
@@ -651,7 +650,7 @@ def get_latest_vcs_version_tag(cfg: config.Config, fetch: bool) -> typ.Optional[
         version_tags = [tag for tag in all_tags if v1version.is_valid(tag, cfg.version_pattern)]
 
     if version_tags:
-        version_tags.sort(key=pkg_resources.parse_version, reverse=True)
+        version_tags.sort(key=version.parse_version, reverse=True)
         _debug_tags = ", ".join(version_tags[:3])
         logger.debug(f"found tags: {_debug_tags} ... ({len(version_tags)} in total)")
         return version_tags[0]
diff --git a/src/bumpver/version.py b/src/bumpver/version.py
index 5c855b6..b344ddb 100644
--- a/src/bumpver/version.py
+++ b/src/bumpver/version.py
@@ -6,11 +6,16 @@
 import typing as typ
 import datetime as dt
 
-import pkg_resources
-
 MaybeInt = typ.Optional[int]
 
 
+def parse_version(version: str) -> typ.Any:
+    # pylint: disable=import-outside-toplevel; lazy import to speed up --help
+    import pkg_resources
+
+    return pkg_resources.parse_version(version)
+
+
 class V1CalendarInfo(typ.NamedTuple):
     """Container for calendar components of version strings."""
 
@@ -171,4 +176,4 @@ def to_pep440(version: str) -> str:
     >>> to_pep440("v201811.0007-beta")
     '201811.7b0'
     """
-    return str(pkg_resources.parse_version(version))
+    return str(parse_version(version))