diff --git a/src/vcf_qc.py b/src/vcf_qc.py
index 09c16bf..4c168cd 100644
--- a/src/vcf_qc.py
+++ b/src/vcf_qc.py
@@ -119,7 +119,7 @@ def get_het_hom_counts(vcf) -> dict:
             print(f"Missing field(s)")
             continue
 
-        if sample_fields['GT'] == (0,0):
+        if sample_fields['GT'] == (0, 0):
             continue
 
         # using the sum of all allele depths instead of the format AD
diff --git a/tests/test_vcf_qc.py b/tests/test_vcf_qc.py
index 3e0fa3c..1139546 100644
--- a/tests/test_vcf_qc.py
+++ b/tests/test_vcf_qc.py
@@ -187,7 +187,7 @@ def test_het_and_hom_ratios_calculated_correctly(self):
         variants
         """
         counts = {
-            'het': [ 0.5, 0.45, 0.55],
+            'het': [0.5, 0.45, 0.55],
             'hom': [1.0, 1.0, 1.0, 1.0, 0.95],
             'x_het': [],
             'x_hom': []
@@ -207,7 +207,7 @@ def test_het_and_hom_ratios_calculated_correctly(self):
 
     def test_x_het_hom_calculated_correctly(self):
         counts = {
-            'het': [ 0.5, 0.45, 0.55],
+            'het': [0.5, 0.45, 0.55],
             'hom': [1.0, 1.0, 1.0, 1.0, 0.95],
             'x_het': [0.45, 0.55],
             'x_hom': [1.0, 0.98]
@@ -313,4 +313,3 @@ def test_expected_dxlink_format_returned(self, mock_job, mock_upload):
             vcf_qc.upload_output_file('test.vcf.qc'),
             {'output_file': {'$dnanexus_link': 'file-xxx'}}
         )
-