diff --git a/src/starfile/functions.py b/src/starfile/functions.py
index 792f666..637268a 100644
--- a/src/starfile/functions.py
+++ b/src/starfile/functions.py
@@ -116,4 +116,4 @@ def to_string(
         quote_character=quote_character,
         quote_all_strings=quote_all_strings,
     )
-    return ''.join(line + '\n' for line in writer.lines())
+    return writer.to_string()
diff --git a/src/starfile/writer.py b/src/starfile/writer.py
index 5c5043d..39efd73 100644
--- a/src/starfile/writer.py
+++ b/src/starfile/writer.py
@@ -66,12 +66,14 @@ def lines(self) -> Generator[str, None, None]:
         yield ''
         for line in self.data_block_generator():
             yield line
+    
+    def to_string(self) -> str:
+        return ''.join(line + '\n' for line in self.lines())
 
     def write(self):
         if self.filename is None:
             raise ValueError('Cannot write nameless file!')
-        with open(self.filename, mode='w+') as f:
-            f.writelines(line + '\n' for line in self.lines())
+        self.filename.write_text(self.to_string())
 
     def data_block_generator(self) -> Generator[str, None, None]:
         for block_name, block in self.data_blocks.items():
@@ -176,7 +178,7 @@ def loop_block(
         float_format=float_format,
         na_rep=na_rep,
         quoting=csv.QUOTE_NONE
-    ).split('\n'):
+    ).splitlines():
         yield line
 
     yield ''
diff --git a/tests/test_parsing.py b/tests/test_parsing.py
index bbe93fa..2ffbdb6 100644
--- a/tests/test_parsing.py
+++ b/tests/test_parsing.py
@@ -1,3 +1,4 @@
+from pathlib import Path
 import time
 
 import pandas as pd
@@ -288,17 +289,15 @@ def test_parse_as_string():
     assert df['rlnResolution'].dtype == 'object'
 
 
-def test_parse_na():
-    import tempfile
+def test_parse_na(tmpdir):
     import starfile
-    parts = pd.DataFrame({"property1":np.arange(10), "property2": np.random.rand(10)})
+
+    parts = pd.DataFrame({"property1": np.arange(10), "property2": np.random.rand(10)})
     parts["property2"].values[-1] *= np.nan
     data = {
-        "particles":parts
+        "particles": parts
     }
-
-    with tempfile.NamedTemporaryFile(mode="w") as tmpfile:
-        starfile.write(data, tmpfile.name) 
-        tmpfile.seek(0)
-        data = starfile.read(tmpfile.name)
-        assert data["property2"].dtype == "float64"
+    tmpfile = Path(tmpdir) / "temp.star"
+    starfile.write(data, tmpfile) 
+    data = starfile.read(tmpfile)
+    assert data["property2"].dtype == "float64"