diff --git a/prometheus_client/__init__.py b/prometheus_client/__init__.py
index 416c25c7..835e5e08 100644
--- a/prometheus_client/__init__.py
+++ b/prometheus_client/__init__.py
@@ -7,7 +7,6 @@
 import os
 import time
 import threading
-from contextlib import contextmanager
 try:
   from BaseHTTPServer import BaseHTTPRequestHandler
 except ImportError:
@@ -25,10 +24,9 @@
 _MINUS_INF = float("-inf")
 
 
-
 class CollectorRegistry(object):
   '''Metric collector registry.
-  
+
   Collectors must have a no-argument method 'collect' that returns a list of
   Metric objects. The returned metrics should be consistent with the Prometheus
   exposition formats.
@@ -58,7 +56,7 @@ def collect(self):
 
   def get_sample_value(self, name, labels=None):
     '''Returns the sample value, or None if not found.
-    
+
     This is inefficient, and intended only for use in unittests.
     '''
     if labels is None:
@@ -75,6 +73,7 @@ def get_sample_value(self, name, labels=None):
 
 _METRIC_TYPES = ('counter', 'gauge', 'summary', 'histogram', 'untyped')
 
+
 class Metric(object):
   '''A single metric and it's samples.'''
   def __init__(self, name, documentation, typ):
@@ -169,10 +168,12 @@ def collect():
 
   return init
 
+
 @_MetricWrapper
 class Counter(object):
   _type = 'counter'
   _reserved_labelnames = []
+
   def __init__(self):
     self._value = 0.0
     self._lock = Lock()
@@ -194,10 +195,14 @@ def count_exceptions(self, exception=Exception):
     class ExceptionCounter(object):
       def __init__(self, counter):
         self._counter = counter
-      def __enter__(self): pass
+
+      def __enter__(self):
+        pass
+
       def __exit__(self, typ, value, traceback):
         if isinstance(value, exception):
           self._counter.inc()
+
       def __call__(self, f):
         @wraps(f)
         def wrapped(*args, **kwargs):
@@ -210,10 +215,12 @@ def _samples(self):
     with self._lock:
       return (('', {}, self._value), )
 
+
 @_MetricWrapper
 class Gauge(object):
   _type = 'gauge'
   _reserved_labelnames = []
+
   def __init__(self):
     self._value = 0.0
     self._lock = Lock()
@@ -247,10 +254,13 @@ def track_inprogress(self):
     class InprogressTracker(object):
       def __init__(self, gauge):
         self._gauge = gauge
+
       def __enter__(self):
         self._gauge.inc()
+
       def __exit__(self, typ, value, traceback):
         self._gauge.dec()
+
       def __call__(self, f):
         @wraps(f)
         def wrapped(*args, **kwargs):
@@ -263,10 +273,12 @@ def _samples(self):
     with self._lock:
       return (('', {}, self._value), )
 
+
 @_MetricWrapper
 class Summary(object):
   _type = 'summary'
   _reserved_labelnames = ['quantile']
+
   def __init__(self):
     self._count = 0.0
     self._sum = 0.0
@@ -286,11 +298,14 @@ def time(self):
     class Timer(object):
       def __init__(self, summary):
         self._summary = summary
+
       def __enter__(self):
         self._start = time.time()
+
       def __exit__(self, typ, value, traceback):
         # Time can go backwards.
         self._summary.observe(max(time.time() - self._start, 0))
+
       def __call__(self, f):
         @wraps(f)
         def wrapped(*args, **kwargs):
@@ -305,6 +320,7 @@ def _samples(self):
           ('_count', {}, self._count),
           ('_sum', {}, self._sum))
 
+
 def _floatToGoString(d):
   if d == _INF:
     return '+Inf'
@@ -313,14 +329,16 @@ def _floatToGoString(d):
   else:
     return repr(d)
 
+
 @_MetricWrapper
 class Histogram(object):
   _type = 'histogram'
   _reserved_labelnames = ['histogram']
+
   def __init__(self, buckets=(.005, .01, .025, .05, .075, .1, .25, .5, .75, 1.0, 2.5, 5.0, 7.5, 10.0, _INF)):
     self._sum = 0.0
     self._lock = Lock()
-    buckets = [float (b) for b in buckets]
+    buckets = [float(b) for b in buckets]
     if buckets != sorted(buckets):
       # This is probably an error on the part of the user,
       # so raise rather than sorting for them.
@@ -349,11 +367,14 @@ def time(self):
     class Timer(object):
       def __init__(self, histogram):
         self._histogram = histogram
+
       def __enter__(self):
         self._start = time.time()
+
       def __exit__(self, typ, value, traceback):
         # Time can go backwards.
         self._histogram.observe(max(time.time() - self._start, 0))
+
       def __call__(self, f):
         @wraps(f)
         def wrapped(*args, **kwargs):
@@ -373,10 +394,11 @@ def _samples(self):
       samples.append(('_sum', {}, self._sum))
       return tuple(samples)
 
-      
+
 CONTENT_TYPE_LATEST = 'text/plain; version=0.0.4; charset=utf-8'
 '''Content type of the latest text format'''
 
+
 def generate_latest(registry=REGISTRY):
     '''Returns the metrics from the registry in latest text format as a string.'''
     output = []
@@ -403,6 +425,7 @@ def do_GET(self):
     self.end_headers()
     self.wfile.write(generate_latest(REGISTRY))
 
+
 def write_to_textfile(path, registry):
   '''Write metrics to the given path.
 
@@ -418,13 +441,13 @@ def write_to_textfile(path, registry):
 if __name__ == '__main__':
   c = Counter('cc', 'A counter')
   c.inc()
- 
+
   g = Gauge('gg', 'A gauge')
   g.set(17)
- 
+
   s = Summary('ss', 'A summary', ['a', 'b'])
   s.labels('c', 'd').observe(17)
- 
+
   h = Histogram('hh', 'A histogram')
   h.observe(.6)
 
diff --git a/tests/test_client.py b/tests/test_client.py
index 535f2e86..7f3dfd49 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -4,6 +4,7 @@
 from prometheus_client import Gauge, Counter, Summary, Histogram
 from prometheus_client import CollectorRegistry, generate_latest
 
+
 class TestCounter(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()
@@ -15,7 +16,7 @@ def test_increment(self):
     self.assertEqual(1, self.registry.get_sample_value('c'))
     self.counter.inc(7)
     self.assertEqual(8, self.registry.get_sample_value('c'))
- 
+
   def test_negative_increment_raises(self):
     self.assertRaises(ValueError, self.counter.inc, -1)
 
@@ -50,6 +51,7 @@ def test_block_decorator(self):
     self.assertTrue(raised)
     self.assertEqual(1, self.registry.get_sample_value('c'))
 
+
 class TestGauge(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()
@@ -66,6 +68,7 @@ def test_gauge(self):
 
   def test_function_decorator(self):
     self.assertEqual(0, self.registry.get_sample_value('g'))
+
     @self.gauge.track_inprogress()
     def f():
       self.assertEqual(1, self.registry.get_sample_value('g'))
@@ -78,6 +81,7 @@ def test_block_decorator(self):
       self.assertEqual(1, self.registry.get_sample_value('g'))
     self.assertEqual(0, self.registry.get_sample_value('g'))
 
+
 class TestSummary(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()
@@ -92,6 +96,7 @@ def test_summary(self):
 
   def test_function_decorator(self):
     self.assertEqual(0, self.registry.get_sample_value('s_count'))
+
     @self.summary.time()
     def f():
       pass
@@ -104,6 +109,7 @@ def test_block_decorator(self):
       pass
     self.assertEqual(1, self.registry.get_sample_value('s_count'))
 
+
 class TestHistogram(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()
@@ -165,6 +171,7 @@ def test_labels(self):
   def test_function_decorator(self):
     self.assertEqual(0, self.registry.get_sample_value('h_count'))
     self.assertEqual(0, self.registry.get_sample_value('h_bucket', {'le': '+Inf'}))
+
     @self.histogram.time()
     def f():
       pass
@@ -180,6 +187,7 @@ def test_block_decorator(self):
     self.assertEqual(1, self.registry.get_sample_value('h_count'))
     self.assertEqual(1, self.registry.get_sample_value('h_bucket', {'le': '+Inf'}))
 
+
 class TestMetricWrapper(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()
@@ -221,6 +229,7 @@ def test_invalid_names_raise(self):
     self.assertRaises(ValueError, Counter, 'c', '', labelnames=['__reserved'])
     self.assertRaises(ValueError, Summary, 'c', '', labelnames=['quantile'])
 
+
 class TestGenerateText(unittest.TestCase):
   def setUp(self):
     self.registry = CollectorRegistry()