Implement the BaseParam class as a base class for PyGMT class-like parameters

Author: seisman

pygmt/params/base.py

@@ -0,0 +1,55 @@
+"""
+Base class for PyGMT common parameters.
+"""
+
+
+class BaseParam:
+    """
+    Base class for PyGMT common parameters.
+
+    Examples
+    --------
+    >>> from typing import Any
+    >>> import dataclasses
+    >>> from pygmt.params.base import BaseParam
+    >>> from pygmt.alias import Alias
+    >>>
+    >>> @dataclasses.dataclass(repr=False)
+    ... class Test(BaseParam):
+    ...     par1: Any = None
+    ...     par2: Any = None
+    ...     par3: Any = None
+    ...
+    ...     _aliases = [
+    ...         Alias("par1"),
+    ...         Alias("par2", prefix="+a"),
+    ...         Alias("par3", prefix="+b", separator="/"),
+    ...     ]
+    >>> var = Test(par1="val1")
+    >>> str(var)
+    'val1'
+    >>> repr(var)
+    "Test(par1='val1')"
+    """
+
+    def __str__(self):
+        """
+        String representation of the object that can be passed to GMT directly.
+        """
+        for alias in self._aliases:
+            alias.value = getattr(self, alias.name)
+        return "".join(
+            [alias.value for alias in self._aliases if alias.value is not None]
+        )
+
+    def __repr__(self):
+        """
+        String representation of the object.
+        """
+        string = []
+        for alias in self._aliases:
+            value = getattr(self, alias.name)
+            if value is None or value is False:
+                continue
+            string.append(f"{alias.name}={value!r}")
+        return f"{self.__class__.__name__}({', '.join(string)})"