Fix some style and import issues.

src/pytest_benchmark/fixture.py

@@ -4,14 +4,26 @@
 import gc
 import sys
 import time
+import traceback
 from math import ceil
 
 from .compat import INT
 from .compat import XRANGE
-from .stats import BenchmarkStats
 from .timers import compute_timer_precision
 from .utils import format_time
 
+try:
+    import statistics
+except (ImportError, SyntaxError):
+    statistics_error = traceback.format_exc()
+    statistics = None
+else:
+    from .stats import BenchmarkStats
+
+
+class FixtureAlreadyUsed(Exception):
+    pass
+
 
 class BenchmarkFixture(object):
     _precisions = {}

src/pytest_benchmark/plugin.py

@@ -30,18 +30,6 @@
 from .utils import parse_timer
 from .utils import parse_warmup
 
-try:
-    import statistics
-except (ImportError, SyntaxError):
-    statistics = False
-    statistics_error = traceback.format_exc()
-else:
-    from .stats import Stats
-
-
-class FixtureAlreadyUsed(Exception):
-    pass
-
 
 def pytest_report_header(config):
     bs = config._benchmarksession
@@ -215,8 +203,6 @@ def pytest_addhooks(pluginmanager):
     method(hookspec)
 
 
-
-
 def pytest_benchmark_compare_machine_info(config, benchmarksession, machine_info, compared_benchmark):
     if compared_benchmark["machine_info"] != machine_info:
         benchmarksession.logger.warn(

src/pytest_benchmark/session.py

@@ -2,10 +2,11 @@
 from __future__ import print_function
 
 import json
-import traceback
 
 import pytest
 
+from .fixture import statistics
+from .fixture import statistics_error
 from .logger import Logger
 from .storage import Storage
 from .table import ResultsTable
@@ -16,14 +17,6 @@
 from .utils import load_timer
 from .utils import short_filename
 
-try:
-    import statistics
-except (ImportError, SyntaxError):
-    statistics = False
-    statistics_error = traceback.format_exc()
-else:
-    from .stats import Stats
-
 
 class PerformanceRegression(pytest.UsageError):
     pass