diff --git a/loop.py b/loop.py
index a0d3778..7d1f2b7 100644
--- a/loop.py
+++ b/loop.py
@@ -1,10 +1,10 @@
 import numpy as np
 import itertools
 
-import recv
 import sampling
 import sigproc
 
+
 class Filter(object):
     def __init__(self, b, a=()):
         self.b = b
@@ -20,6 +20,7 @@ class Filter(object):
         self.y = [y] + self.y
         return y
 
+
 class FreqLoop(object):
     def __init__(self, x, freqs, prefix=0.0):
         interp = sampling.Interpolator()
@@ -34,7 +35,8 @@ class FreqLoop(object):
 
         samplers = itertools.tee(self.sampler, len(freqs))
         for freq, generator in zip(freqs, samplers):
-            self.gens.append( sigproc.extract_symbols(generator, freq) )
+            gen = sigproc.extract_symbols(generator, freq)
+            self.gens.append(gen)
 
         Kp, Ki = 0.2, 0.01
         b = np.array([1, -1])*Kp + np.array([0.5, 0.5])*Ki
diff --git a/sampling.py b/sampling.py
index eb7af47..dbccfdb 100644
--- a/sampling.py
+++ b/sampling.py
@@ -3,6 +3,7 @@ import logging
 
 log = logging.getLogger(__name__)
 
+
 class Interpolator(object):
     def __init__(self, resolution=10000, width=128):
         self.width = width
@@ -28,6 +29,7 @@ class Interpolator(object):
         coeffs = self.filt[j]
         return coeffs, k - self.width
 
+
 class Sampler(object):
     def __init__(self, src, interp=None):
         self.src = iter(src)
@@ -70,6 +72,6 @@ if __name__ == '__main__':
     _, x = common.load(sys.stdin)
     sampler = Sampler(x, Interpolator())
     sampler.freq += df
-    y = np.array(list(sampler), )
-    sys.stdout.write( common.dumps(y*1j) )
-
+    y = np.array(list(sampler))
+    y = common.dumps(y*1j)
+    sys.stdout.write(y)
diff --git a/test_sampling.py b/test_sampling.py
index 5e85873..bbac0eb 100644
--- a/test_sampling.py
+++ b/test_sampling.py
@@ -1,6 +1,6 @@
 import sampling
 import numpy as np
-import pylab
+
 
 def test_resample():
     x = np.arange(300)
@@ -12,7 +12,8 @@ def test_resample():
     err = x - y
     assert np.max(np.abs(err)) < 1e-10
 
+
 def test_coeffs():
     I = sampling.Interpolator(width=4, resolution=16)
-    err = I.filt[0] - [0,0,0,1,0,0,0,0]
+    err = I.filt[0] - [0, 0, 0, 1, 0, 0, 0, 0]
     assert np.max(np.abs(err)) < 1e-10
diff --git a/test_sigproc.py b/test_sigproc.py
index a961c2e..6cf8750 100644
--- a/test_sigproc.py
+++ b/test_sigproc.py
@@ -4,6 +4,7 @@ import common
 import numpy as np
 import random
 
+
 def test_qam():
     q = sigproc.QAM(sigproc._symbols)
     r = random.Random(0)
@@ -13,6 +14,7 @@ def test_qam():
     decoded = list(q.decode(list(S)))
     assert decoded == bits
 
+
 def test_drift():
     fc = 10e3
     df = 1.23