(#32) Enable setting screenshot file name prefix

Mainframe3270/x3270.py

@@ -209,21 +209,25 @@ def set_screenshot_folder(self, path: str) -> None:
             logger.warn('Screenshots will be saved in "%s"' % self.imgfolder)
 
     @keyword("Take Screenshot")
-    def take_screenshot(self, height: int = 410, width: int = 670) -> str:
+    def take_screenshot(
+        self, height: int = 410, width: int = 670, filename_prefix: str = "screenshot"
+    ) -> str:
         """Generate a screenshot of the IBM 3270 Mainframe in a html format. The
         default folder is the log folder of RobotFramework, if you want change see the `Set Screenshot Folder`.
 
         The Screenshot is printed in a iframe log, with the values of height=410 and width=670, you
-        can change this values passing them to the keyword.
+        can change these values by passing them to the keyword.
+
+        The file name prefix can be set, the default is "screenshot".
 
         The full file path is returned.
 
         Example:
             | ${filepath} | Take Screenshot |
             | ${filepath} | Take Screenshot | height=500 | width=700 |
             | Take Screenshot | height=500 | width=700 |
+            | Take Screenshot | filename_prefix=MyScreenshot |
         """
-        filename_prefix = "screenshot"
         extension = "html"
         filename_sufix = round(time.time() * 1000)
         filepath = os.path.join(

utest/x3270/test_screenshot.py

@@ -43,3 +43,15 @@ def test_take_screenshot(mocker: MockerFixture, under_test: x3270):
         assert filepath == r".\screenshot_1000.html"
     else:
         assert filepath == "./screenshot_1000.html"
+
+    filepath = under_test.take_screenshot(250, 250, "MyScreenshot")
+
+    logger.write.assert_called_with(
+        '<iframe src="./MyScreenshot_1000.html" height="250" width="250"></iframe>',
+        level="INFO",
+        html=True,
+    )
+    if os.name == "nt":
+        assert filepath == r".\MyScreenshot_1000.html"
+    else:
+        assert filepath == "./MyScreenshot_1000.html"