add pretty_text (#220)

* add pretty_text

* add test cases

* add argument indent

* change pretty_text to property

* fixed format end

mmcv/utils/config.py

@@ -191,6 +191,68 @@ class Config(object):
     def text(self):
         return self._text
 
+    @property
+    def pretty_text(self):
+
+        indent = 4
+
+        def _indent(s_, num_spaces):
+            s = s_.split('\n')
+            if len(s) == 1:
+                return s_
+            first = s.pop(0)
+            s = [(num_spaces * ' ') + line for line in s]
+            s = '\n'.join(s)
+            s = first + '\n' + s
+            return s
+
+        def _format_basic_types(k, v):
+            if isinstance(v, str):
+                v_str = "'{}'".format(v)
+            else:
+                v_str = str(v)
+            attr_str = '{}={}'.format(str(k), v_str)
+            attr_str = _indent(attr_str, indent)
+
+            return attr_str
+
+        def _format_list(k, v):
+            # check if all items in the list are dict
+            if all(isinstance(_, dict) for _ in v):
+                v_str = '[\n'
+                v_str += '\n'.join(
+                    'dict({}),'.format(_indent(_format_dict(v_), indent))
+                    for v_ in v).rstrip(',')
+                attr_str = '{}={}'.format(str(k), v_str)
+                attr_str = _indent(attr_str, indent) + ']'
+            else:
+                attr_str = _format_basic_types(k, v)
+            return attr_str
+
+        def _format_dict(d, outest_level=False):
+            r = ''
+            s = []
+            for idx, (k, v) in enumerate(d.items()):
+                is_last = idx >= len(d) - 1
+                end = '' if outest_level or is_last else ','
+                if isinstance(v, dict):
+                    v_str = '\n' + _format_dict(v)
+                    attr_str = '{}=dict({}'.format(str(k), v_str)
+                    attr_str = _indent(attr_str, indent) + ')' + end
+                elif isinstance(v, list):
+                    attr_str = _format_list(k, v) + end
+                else:
+                    attr_str = _format_basic_types(k, v) + end
+
+                s.append(attr_str)
+            r += '\n'.join(s)
+            return r
+
+        cfg_dict = self._cfg_dict.to_dict()
+        text = _format_dict(cfg_dict, outest_level=True)
+
+        return text
+
     def __repr__(self):
         return 'Config (path: {}): {}'.format(self.filename,
                                               self._cfg_dict.__repr__())

tests/data/config/l.py

-_base_ = ['./l1.py', './l2.yaml', './l3.json']
+_base_ = ['./l1.py', './l2.yaml', './l3.json', './l4.py']
 item3 = False
 item4 = 'test'

tests/data/config/l4.py

+item5 = dict(a=0, b=1)
+item6 = [dict(a=0), dict(b=1)]
+item7 = dict(a=[0, 1, 2], b=dict(c=[3.1, 4.2, 5.3]))

tests/test_config.py

@@ -2,6 +2,7 @@
 import json
 import os.path as osp
 import sys
+import tempfile
 
 import pytest
 
@@ -78,6 +79,9 @@ def test_merge_from_multiple_bases():
     assert cfg.item2.a == 0
     assert cfg.item3 is False
     assert cfg.item4 == 'test'
+    assert cfg.item5 == dict(a=0, b=1)
+    assert cfg.item6 == [dict(a=0), dict(b=1)]
+    assert cfg.item7 == dict(a=[0, 1, 2], b=dict(c=[3.1, 4.2, 5.3]))
 
     with pytest.raises(KeyError):
         Config.fromfile(osp.join(osp.dirname(__file__), 'data/config/m.py'))
@@ -171,3 +175,14 @@ def test_setattr():
     assert cfg.item2.a == 0
     assert cfg._cfg_dict['item5'] == {'a': {'b': None}}
     assert cfg.item5.a.b is None
+
+
+def test_pretty_text():
+    cfg_file = osp.join(osp.dirname(__file__), 'data/config/l.py')
+    cfg = Config.fromfile(cfg_file)
+    with tempfile.TemporaryDirectory() as temp_config_dir:
+        text_cfg_filename = osp.join(temp_config_dir, '_text_config.py')
+        with open(text_cfg_filename, 'w') as f:
+            f.write(cfg.pretty_text)
+        text_cfg = Config.fromfile(text_cfg_filename)
+    assert text_cfg._cfg_dict == cfg._cfg_dict