Updates

pygmt/src/timestamp.py

@@ -1,8 +1,9 @@
 """
 timestamp - Plot the GMT timestamp logo.
 """
+from packaging.version import Version
 from pygmt.clib import Session
-from pygmt.helpers import is_nonstr_iter
+from pygmt.helpers import build_arg_string, is_nonstr_iter
 
 __doctest_skip__ = ["timestamp"]
 
@@ -22,36 +23,48 @@ def timestamp(
         that is a combination of a horizontal (**L**(eft), **C**(enter), or
         **R**(ight)) and a vertical (**T**(op), **M**(iddle), or **B**(ottom))
         code.
-    offset : str or list of str
+    offset : str or list
         (*offset_x*, *offset_y*) or *offset*.
-        Offset the anchor point for the timestamp by *offset_x* and *offset_y*.
+        Offset the anchor point of the timestamp by *offset_x* and *offset_y*.
         If a single value *offset* is given, *offset_y*=*offset_x*=*offset*.
-    font : str or int
+    font : str
         Font name or font number of the timestamp and the optional label .
 
-    Example
-    -------
+    Examples
+    --------
     >>> # Plot the GMT timestamp logo.
     >>> import pygmt
     >>> fig = pygmt.Figure()
     >>> fig.timestamp()
     >>> fig.show()
+
+    >>> # Plot the GMT timestamp logo with a custom label.
+    >>> fig = pygmt.Figure()
+    >>> fig.timestamp(label="Powered by PyGMT")
+    >>> fig.show()
     """
     self._preprocess()  # pylint: disable=protected-access
 
+    kwdict = {}
+    kwdict["T"] = True  # pass the -T option to the plot module
+    kwdict["U"] = True
+
+    # build the argument for the -U option
     label = "" if label is None else f"{label}"
-    uarg = f"{label}+j{justification}"
+    kwdict["U"] = f"{label}+j{justification}"
 
-    if is_nonstr_iter(offset):
-        uarg += "+o" + "/".join(f"{item}" for item in offset)
+    if is_nonstr_iter(offset):  # given a list
+        kwdict["U"] += "+o" + "/".join(f"{item}" for item in offset)
     else:
+        kwdict["U"] += f"+o{offset}"
         if "/" not in offset:
-            # only one offset is given
-            # Workaround for an upstream bug which will be fixed in GMT 6.5.0.
+            # Giving a single offset doesn't work in GMT <= 6.4.0.
             # See https://github.com/GenericMappingTools/gmt/issues/7107.
-            uarg += f"+o{offset}/{offset}"
-        else:
-            uarg += f"+o{offset}"
+            with Session() as lib:
+                if Version(lib.info["version"]) < Version("6.5.0"):
+                    kwdict["U"] += "/{offset}"
 
     with Session() as lib:
-        lib.call_module(module="plot", args=f"-U{uarg} -T --FONT_LOGO={font}")
+        lib.call_module(
+            module="plot", args=build_arg_string(kwdict) + f" --FONT_LOGO={font}"
+        )