diff --git a/utests/test_log.py b/utests/test_log.py
index 6465007..41e95dd 100644
--- a/utests/test_log.py
+++ b/utests/test_log.py
@@ -103,34 +103,26 @@ def test_log_response(mocked_logger):
 
 
 def test_format_data_to_log_string_truncated_1():
-    data = ''
-    for i in range(0, 10000):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 10000))
     truncated = format_data_to_log_string(data, 9999)
     assert truncated == data[:9999] + '... (set the log level to DEBUG or TRACE to see the full content)'
 
 
 def test_format_data_to_log_string_truncated_2():
-    data = ''
-    for i in range(0, 10):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 10))
     truncated = format_data_to_log_string(data, 0)
     assert truncated == '... (set the log level to DEBUG or TRACE to see the full content)'
 
 
 def test_format_data_to_log_string_truncated_3():
-    data = ''
-    for i in range(0, 10):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 10))
     truncated = format_data_to_log_string(data, 10)
     assert truncated == data
 
 
 @mock.patch('HttpxLibrary.log.logging')
 def test_format_data_not_truncate_debug_level(mocked_logger):
-    data = ''
-    for i in range(0, 100001):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 100001))
     mocked_logger.getLogger().level = 10
     truncated = format_data_to_log_string(data)
     assert truncated == data
@@ -138,9 +130,7 @@ def test_format_data_not_truncate_debug_level(mocked_logger):
 
 @mock.patch('HttpxLibrary.log.logging')
 def test_format_data_not_truncate_trace_level(mocked_logger):
-    data = ''
-    for i in range(0, 100001):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 100001))
     mocked_logger.getLogger().level = 0
     truncated = format_data_to_log_string(data)
     assert truncated == data
@@ -148,9 +138,7 @@ def test_format_data_not_truncate_trace_level(mocked_logger):
 
 @mock.patch('HttpxLibrary.log.logging')
 def test_format_data_truncate_info_level(mocked_logger):
-    data = ''
-    for i in range(0, 100001):
-        data = data + str(i)
+    data = ''.join(str(i) for i in range(0, 100001))
     mocked_logger.getLogger().level = 20
     truncated = format_data_to_log_string(data)
     assert truncated == data[:10000] + '... (set the log level to DEBUG or TRACE to see the full content)'