add DotEnv dumps/dump

src/dotenv/main.py

@@ -113,6 +113,43 @@ def get(self, key: str) -> Optional[str]:
 
         return None
 
+    def from_dict(self, data: Dict[str, Optional[str]], override: bool = False) -> None:
+        """
+        Create a DotEnv from a dictionary.
+        """
+        for key, value in data.items():
+            if value is not None:
+                if not override and key in self.dict().keys():
+                    if self.verbose:
+                        logger.warning(
+                            "Key %s already exists and will not be overwritten.",
+                            key,
+                        )
+                    continue
+
+                if not self._dict:
+                    self._dict = OrderedDict()
+                self._dict[key] = value
+
+    def dumps(self) -> str:
+        """
+        Serialize the instance as a string.
+        """
+        output = ""
+        for k, v in self.dict().items():
+            if v is not None:
+                output += f"{k}={v}\n"
+        return output
+
+    def dump(self) -> None:
+        """
+        Write the instance to the .env file.
+        """
+
+        if self.dotenv_path and os.path.isfile(self.dotenv_path):
+            with open(self.dotenv_path, "w", encoding=self.encoding) as f:
+                f.write(self.dumps())
+
 
 def get_key(
     dotenv_path: StrPath,

tests/test_main.py

@@ -3,6 +3,7 @@
 import os
 import sys
 import textwrap
+from typing import Dict, Optional
 from unittest import mock
 
 import pytest
@@ -399,3 +400,17 @@ def test_dotenv_values_file_stream(dotenv_path):
         result = dotenv.dotenv_values(stream=f)
 
     assert result == {"a": "b"}
+
+
+def test_from_dict_and_dumps(dotenv_path):
+    data: Dict[str, Optional[str]] = {"a": "b", "c": "d"}
+
+    de = dotenv.main.DotEnv(dotenv_path)
+    de.from_dict(data)
+    de_str = de.dumps()
+
+    assert de_str == "a=b\nc=d\n"
+
+    de.dump()
+
+    assert dotenv_path.read_text() == de_str