diff --git a/fluents/dataset.py b/fluents/dataset.py
index a827321..8722c6e 100644
--- a/fluents/dataset.py
+++ b/fluents/dataset.py
@@ -444,6 +444,11 @@ def write_ftsv(fd, ds):
     @param ds: The dataset to be written. The function handles datasets
     of these classes: Dataset, CategoryDataset and GraphDataset
     """
+    opened = False
+    if isinstance(fd, str):
+        fd = open(fd, 'w')
+        opened = True
+
     # Write header information
     if isinstance(ds, CategoryDataset):
         type = 'category'
@@ -475,6 +480,8 @@ def write_ftsv(fd, ds):
             print >> fd, "%s\t" % m[j, i], 
         print >> fd
 
+    if opened:
+        fd.close()
 
 def read_ftsv(fd):
     """Read a dataset in fluents tab separated values (ftsv) form and return it.
@@ -483,6 +490,11 @@ def read_ftsv(fd):
     @return: A Dataset, CategoryDataset or GraphDataset depending on the information
     read.
     """
+    opened = False
+    if isinstance(fd, str):
+        fd = open(fd)
+        opened = True
+
     split_re = re.compile('^#\s*(\w+)\s*:\s*(.+)')
     dimensions = []
     identifiers = {}
@@ -548,5 +560,9 @@ def read_ftsv(fd):
     else:
         ds = Dataset(matrix, dims, name)
 
+    if opened:
+        fd.close()
+
     return ds
 
+