Well, I am a bit curious, so I just tested the 3 myself right after asking the question ;-)
Ok, this is not a very serious review but here is what I can say :
I tried the tools with the default settings (it's important because you can pretty much choose your check rules) on the following script :
#!/usr/local/bin/python
# by Daniel Rosengren modified by e-satis
import sys, time
stdout = sys.stdout
BAILOUT = 16
MAX_ITERATIONS = 1000
class Iterator(object) :
def __init__(self):
print 'Rendering...'
for y in xrange(-39, 39):
stdout.write('\n')
for x in xrange(-39, 39):
if self.mandelbrot(x/40.0, y/40.0) :
stdout.write(' ')
else:
stdout.write('*')
def mandelbrot(self, x, y):
cr = y - 0.5
ci = x
zi = 0.0
zr = 0.0
for i in xrange(MAX_ITERATIONS) :
temp = zr * zi
zr2 = zr * zr
zi2 = zi * zi
zr = zr2 - zi2 + cr
zi = temp + temp + ci
if zi2 + zr2 > BAILOUT:
return i
return 0
t = time.time()
Iterator()
print '\nPython Elapsed %.02f' % (time.time() - t)
As a result :
PyChecker is troublesome because it compiles the module to analyze it. If you don't want your code to run (e.g, it performs a SQL query), that's bad.PyFlakes is supposed to be lite. Indeed, it decided that the code was perfect. I am looking for something quite severe so I don't think I'll go for it.PyLint has been very talkative and rated the code 3/10 (OMG, I'm a dirty coder !).
Strongs points of PyLint:
- Very descriptive and accurate report.
- Detect some code smells. Here it told me to drop my class to write something with functions because the OO approach was useless in this specific case. Something I knew, but never expected a computer to tell me :-p
- The fully corrected code run faster (no class, no reference binding...).
- Made by a French team. Ok it's not a plus for everybody, but I like it ;-)
Cons of PyLint:
- Some rules are really strict. I know that you can change it and that the default is to match PEP8, but is it such a crime to write 'for x in seq'? Apparently yes because you can't write a variable name with less than 3 letters. I will change that.
- Very very talkative. Be ready to use your eyes.
Corrected script (with lazy doc strings and variable names) :
#!/usr/local/bin/python
# by Daniel Rosengren, modified by e-satis
"""
Module doctring
"""
import time
from sys import stdout
BAILOUT = 16
MAX_ITERATIONS = 1000
def mandelbrot(dim_1, dim_2):
"""
function doc string
"""
cr1 = dim_1 - 0.5
ci1 = dim_2
zi1 = 0.0
zr1 = 0.0
for i in xrange(MAX_ITERATIONS) :
temp = zr1 * zi1
zr2 = zr1 * zr1
zi2 = zi1 * zi1
zr1 = zr2 - zi2 + cr1
zi1 = temp + temp + ci1
if zi2 + zr2 > BAILOUT:
return i
return 0
def execute() :
"""
func doc string
"""
print 'Rendering...'
for dim_1 in xrange(-39, 39):
stdout.write('\n')
for dim_2 in xrange(-39, 39):
if mandelbrot(dim_1/40.0, dim_2/40.0) :
stdout.write(' ')
else:
stdout.write('*')
START_TIME = time.time()
execute()
print '\nPython Elapsed %.02f' % (time.time() - START_TIME)
EDIT :
Thanks to Rudiger Wolf, I discovered pep8 that does exactly what its name suggests: matching PEP8. It has found several syntax no-nos that PyLint did not. But PyLint found stuff that was not specifically linked to PEP8 but interesting. Both tools are interesting and complementary.
Eventually I will use both since there are really easy to install (via packages or setuptools) and the output text is so easy to chain.
To give you a little idea of their output:
pep8:
./python_mandelbrot.py:4:11: E401 multiple imports on one line
./python_mandelbrot.py:10:1: E302 expected 2 blank lines, found 1
./python_mandelbrot.py:10:23: E203 whitespace before ':'
./python_mandelbrot.py:15:80: E501 line too long (108 characters)
./python_mandelbrot.py:23:1: W291 trailing whitespace
./python_mandelbrot.py:41:5: E301 expected 1 blank line, found 3
PyLint:
************* Module python_mandelbrot
C: 15: Line too long (108/80)
C: 61: Line too long (85/80)
C: 1: Missing docstring
C: 5: Invalid name "stdout" (should match (([A-Z_][A-Z0-9_]*)|(__.*__))$)
C: 10:Iterator: Missing docstring
C: 15:Iterator.__init__: Invalid name "y" (should match [a-z_][a-z0-9_]{2,30}$)
C: 17:Iterator.__init__: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)
[...] and a very long report with useful stats like :
Duplication
-----------
+-------------------------+------+---------+-----------+
| |now |previous |difference |
+=========================+======+=========+===========+
|nb duplicated lines |0 |0 |= |
+-------------------------+------+---------+-----------+
|percent duplicated lines |0.000 |0.000 |= |
+-------------------------+------+---------+-----------+
