[Feature] Add print_config.py to the tools (open-mmlab#1547)

* add print_config.py to the tools

* fix bugs

tools/analysis_tools/print_config.py

@@ -0,0 +1,36 @@
+# Copyright (c) OpenMMLab. All rights reserved.
+import argparse
+
+from mmengine import Config, DictAction
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description='Print the whole config')
+    parser.add_argument('config', help='config file path')
+    parser.add_argument(
+        '--cfg-options',
+        nargs='+',
+        action=DictAction,
+        help='override some settings in the used config, the key-value pair '
+        'in xxx=yyy format will be merged into config file. If the value to '
+        'be overwritten is a list, it should be like key="[a,b]" or key=a,b '
+        'It also allows nested list/tuple values, e.g. key="[(a,b),(c,d)]" '
+        'Note that the quotation marks are necessary and that no white space '
+        'is allowed.')
+    args = parser.parse_args()
+
+    return args
+
+
+def main():
+    args = parse_args()
+
+    cfg = Config.fromfile(args.config)
+
+    if args.cfg_options is not None:
+        cfg.merge_from_dict(args.cfg_options)
+    print(f'Config:\n{cfg.pretty_text}')
+
+
+if __name__ == '__main__':
+    main()