Replace pkg_resources with importlib.metadata

pygmt/__init__.py

@@ -19,8 +19,7 @@
 """
 
 import atexit as _atexit
-
-from pkg_resources import get_distribution
+from importlib.metadata import version
 
 # Import modules to make the high-level GMT Python API
 from pygmt import datasets
@@ -63,7 +62,7 @@
 )
 
 # Get semantic version through setuptools-scm
-__version__ = f'v{get_distribution("pygmt").version}'  # e.g. v0.1.2.dev3+g0ab3cd78
+__version__ = version("pygmt")  # e.g. v0.1.2.dev3+g0ab3cd78
 __commit__ = __version__.split("+g")[-1] if "+g" in __version__ else ""  # 0ab3cd78
 
 # Start our global modern mode session
@@ -135,10 +134,10 @@ def _get_ghostscript_version():
 
         for gs_cmd in cmds:
             try:
-                version = subprocess.check_output(
+                gs_version = subprocess.check_output(
                     [gs_cmd, "--version"], universal_newlines=True
                 ).strip()
-                return version
+                return gs_version
             except FileNotFoundError:
                 continue
         return None
@@ -148,10 +147,10 @@ def _get_gmt_version():
         Get GMT version.
         """
         try:
-            version = subprocess.check_output(
+            gmt_version = subprocess.check_output(
                 ["gmt", "--version"], universal_newlines=True
             ).strip()
-            return version
+            return gmt_version
         except FileNotFoundError:
             return None