PYCHECKER(1)

NAME
pychecker - program to check python scripts for common mistakes

SYNOPSIS
pychecker [options] files...

DESCRIPTION
This manual page documents briefly the pychecker command. It was written for the Debian GNU/Linux distribution because the original program does not have a manual page.

pychecker is a program that finds common bugs in python source code. It finds problems that are typically caught by a compiler for less dynamic languages, like C and C++. Because of the dynamic nature of python, some warnings may be incorrect; however, spurious warnings should be fairly infrequent.

pychecker works in a combination of ways. First, it imports each module. If there is an import error, the module cannot be processed. The import provides some basic information about the module. The code for each function, class, and method is checked for possible problems.

CHOICE OF PYTHON VERSION

By default, the /usr/bin/pychecker script executes pychecker using the default Python interpreter in /usr/bin/python. Some users may want to run pychecker with a different Python interpreter. To accommodate this, the
 /usr/bin/pychecker script supports the use of $PYTHONVER on the command-line, i.e.

PYTHONVER=2.3 pychecker file.py

If $PYTHONVER is set, /usr/bin/pychecker will attempt to execute pychecker using /usr/bin/python$PYTHONVER instead of /usr/bin/python.

Note, however, that this will only work for versions of the python interpreter supported by the current Debian Python infrastructure, not for any arbitrary Python interpreter installed in /usr/bin.

OPTIONS
Long options can be preceded with no- to turn off (e.g., no-namedargs). Default settings are indicated by [brackets]

  Major Options:

--only
    only warn about files passed on the command line [off]

-e, --level
    the maximum error level of warnings to be displayed

-#, --limit
    the maximum number of warnings to be displayed [10]

-F, --config
    specify .pycheckrc file to use

--quixote
    support Quixote's PTL modules

--evil
    list of evil C extensions that crash the interpreter [[]]

  Error Control:

-i, --import
    unused imports [on]

-k, --pkgimport
    unused imports from __init__.py [on]

-M, --reimportself module imports itself [on]

-X, --reimport
    reimporting a module [on]

-x, --miximport
    module does import and from ... import [on]

-l, --local
    unused local variables, except tuples [on]

-t, --tuple
    all unused local variables, including tuples [off]

-9, --members
    all unused class data members [off]

-v, --var
    all unused module variables [off]

-p, --privatevar
    unused private module variables [on]

-g, --allglobals
    report each occurrence of global warnings [off]

-n, --namedargs
    functions called with named arguments (like keywords) [off]

-a, --initattr
    Attributes (members) must be defined in __init__() [off]

-I, --initsubclass Subclass.__init__() not defined [off]

-u, --callinit
    Baseclass.__init__() not called [on]

-0, --abstract
    Subclass needs to override methods that only throw exceptions [on]

-N, --initreturn
    Return None from __init__() [on]

-8, --unreachable
    unreachable code [off]

-2, --constCond
    a constant is used in a conditional statement [on]

-1, --constant1
    1 is used in a conditional statement (if 1: or while 1:) [off]

--stringiter
    check if iterating over a string [on]

--stringfind
    check improper use of string.find() [on]

-A, --callattr
    Calling data members as functions [off]

-y, --classattr
    class attribute does not exist [on]

-S, --self
    First argument to methods [self]

--classmethodargs First argument to classmethods [['cls', 'klass']]

-T, --argsused
    unused method/function arguments [on]

-z, --varargsused
    unused method/function variable arguments [on]

-G, --selfused
    ignore if self is unused in methods [off]

-o, --override
    check if overridden methods have the same signature [on]

--special
    check if __special__ methods exist and have the correct signature [on]

-U, --reuseattr
    check if function/class/method names are reused [on]

-Y, --positive
    check if using unary positive (+) which is usually meaningless [on]

-j, --moddefvalue
    check if modify (call method) on a parameter that has a default value [on]

--changetypes
    check if variables are set to different types [off]

--unpack
    check if unpacking a non-sequence [on]

--unpacklen
    check if unpacking sequence with the wrong length [on]

--badexcept
    check if raising or catching bad exceptions [on]

-4, --noeffect
    check if statement appears to have no effect [on]

--modulo1
    check if using (expr % 1), it has no effect on integers and strings [on]

--isliteral
    check if using (expr is const-literal), doesn't always work on integers and strings [on]

  Possible Errors:

-r, --returnvalues check consistent return values [on]

-C, --implicitreturns check if using implict and explicit return values [on]

-O, --objattrs
    check that attributes of objects exist [on]

-7, --slots
    various warnings about incorrect usage of __slots__ [on]

-3, --properties
    using properties with classic classes [on]

--emptyslots
    check if __slots__ is empty [on]

-D, --intdivide
    check if using integer division [on]

-w, --shadow
    check if local variable shadows a global [on]

-s, --shadowbuiltin check if a variable shadows a builtin [on]

  Security:

--input
    check if input() is used [on]

-6, --exec
    check if the exec statement is used [off]

  Suppressions:

-q, --stdlib
    ignore warnings from files under standard library [off]

-b, --blacklist
    ignore warnings from the list of modules [['Tkinter', 'wxPython', 'gtk', 'GTK', 'GDK']]

-Z, --varlist
    ignore global variables not used if name is one of these values [['__version__', '__warningregistry__', '__all__', '__credits__', '__test__', '__author__', '__email__', '__revision__', '__id__', '__copyright__', '__license__', '__date__']]

-E, --unusednames
    ignore unused locals/arguments if name is one of these values [['_', 'empty', 'unused', 'dummy']]

--deprecated
    ignore use of deprecated modules/functions [on]

  Complexity:

-L, --maxlines
    maximum lines in a function [200]

-B, --maxbranches
    maximum branches in a function [50]

-R, --maxreturns
    maximum returns in a function [10]

-J, --maxargs
    maximum # of arguments to a function [10]

-K, --maxlocals
    maximum # of locals in a function [40]

-5, --maxrefs
    maximum # of identifier references (Law of Demeter) [5]

-m, --moduledoc
    no module doc strings [off]

-c, --classdoc
    no class doc strings [off]

-f, --funcdoc
    no function/method doc strings [off]

  Debug:

--rcfile
    print a .pycheckrc file generated from command line args

-P, --printparse
    print internal checker parse structures [off]

-d, --debug
    turn on debugging for checker [off]

-Q, --quiet
    turn off all output except warnings [off]

-V, --version
    print the version of PyChecker and exit

AUTHOR
Pychecker was written by Neal Norwitz and Eric C. Newton. Other contributors are listed in /usr/share/doc/pychecker/MAINTAINERS This manual page was written by Fredrik Steen <stone@debian.org> for the Debian GNU/Linux system (but may be used by others). It has been subsequently modified by Kenneth J. Pronovici <pronovic@debian.org>.

SEE ALSO
python(1) Running pychecker --help may provide more complete documentation of program options. The pychecker web page at <http://pychecker.sourceforge.net> contains some guidance on using the program.