Fixers

Each step of transforming code is encapsulated in a fixer. The command python -m fissix -l lists them. Each can be turned on and off individually. They are described here in more detail.

apply

Removes usage of apply(). For example apply(function, *args, **kwargs) is converted to function(*args, **kwargs).

asserts

Replaces deprecated unittest method names with the correct ones.

From	To
failUnlessEqual(a, b)	assertEqual(a, b)
assertEquals(a, b)	assertEqual(a, b)
failIfEqual(a, b)	assertNotEqual(a, b)
assertNotEquals(a, b)	assertNotEqual(a, b)
failUnless(a)	assertTrue(a)
assert_(a)	assertTrue(a)
failIf(a)	assertFalse(a)
failUnlessRaises(exc, cal)	assertRaises(exc, cal)
failUnlessAlmostEqual(a, b)	assertAlmostEqual(a, b)
assertAlmostEquals(a, b)	assertAlmostEqual(a, b)
failIfAlmostEqual(a, b)	assertNotAlmostEqual(a, b)
assertNotAlmostEquals(a, b)	assertNotAlmostEqual(a, b)

basestring

Converts basestring to str.

buffer

Converts buffer to memoryview. This fixer is optional because the memoryview API is similar but not exactly the same as that of buffer.

dict

Fixes dictionary iteration methods. dict.iteritems() is converted to dict.items(), dict.iterkeys() to dict.keys(), and dict.itervalues() to dict.values(). Similarly, dict.viewitems(), dict.viewkeys() and dict.viewvalues() are converted respectively to dict.items(), dict.keys() and dict.values(). It also wraps existing usages of dict.items(), dict.keys(), and dict.values() in a call to list.

except

Converts except X, T to except X as T.

exec

Converts the exec statement to the exec() function.

execfile

Removes usage of execfile(). The argument to execfile() is wrapped in calls to open(), compile(), and exec().

exitfunc

Changes assignment of sys.exitfunc to use of the atexit module.

filter

Wraps filter() usage in a list call.

funcattrs

Fixes function attributes that have been renamed. For example, my_function.func_closure is converted to my_function.__closure__.

future

Removes from __future__ import new_feature statements.

getcwdu

Renames os.getcwdu() to os.getcwd().

has_key

Changes dict.has_key(key) to key in dict.

idioms

This optional fixer performs several transformations that make Python code more idiomatic. Type comparisons like type(x) is SomeClass and type(x) == SomeClass are converted to isinstance(x, SomeClass). while 1 becomes while True. This fixer also tries to make use of sorted() in appropriate places. For example, this block

L = list(some_iterable)
L.sort()

is changed to

L = sorted(some_iterable)

import

Detects sibling imports and converts them to relative imports.

imports

Handles module renames in the standard library.

imports2

Handles other modules renames in the standard library. It is separate from the :attribute:`imports` fixer only because of technical limitations.

input

Converts input(prompt) to eval(input(prompt)).

intern

Converts intern() to sys.intern().

isinstance

Fixes duplicate types in the second argument of isinstance(). For example, isinstance(x, (int, int)) is converted to isinstance(x, int) and isinstance(x, (int, float, int)) is converted to isinstance(x, (int, float)).

itertools_imports

Removes imports of itertools.ifilter(), itertools.izip(), and itertools.imap(). Imports of itertools.ifilterfalse() are also changed to itertools.filterfalse().

itertools

Changes usage of itertools.ifilter(), itertools.izip(), and itertools.imap() to their built-in equivalents. itertools.ifilterfalse() is changed to itertools.filterfalse().

long

Renames long to int.

map

Wraps map() in a list call. It also changes map(None, x) to list(x). Using from future_builtins import map disables this fixer.

metaclass

Converts the old metaclass syntax (__metaclass__ = Meta in the class body) to the new (class X(metaclass=Meta)).

methodattrs

Fixes old method attribute names. For example, meth.im_func is converted to meth.__func__.

ne

Converts the old not-equal syntax, <>, to !=.

next

Converts the use of iterator’s next() methods to the next() function. It also renames next() methods to __next__().

nonzero

Renames __nonzero__() to __bool__().

numliterals

Converts octal literals into the new syntax.

operator

Converts calls to various functions in the operator module to other, but equivalent, function calls. When needed, the appropriate import statements are added, e.g. import collections.abc. The following mapping are made:

From	To
operator.isCallable(obj)	callable(obj)
operator.sequenceIncludes(obj)	operator.contains(obj)
operator.isSequenceType(obj)	isinstance(obj, collections.abc.Sequence)
operator.isMappingType(obj)	isinstance(obj, collections.abc.Mapping)
operator.isNumberType(obj)	isinstance(obj, numbers.Number)
operator.repeat(obj, n)	operator.mul(obj, n)
operator.irepeat(obj, n)	operator.imul(obj, n)

paren

Add extra parenthesis where they are required in list comprehensions. For example, [x for x in 1, 2] becomes [x for x in (1, 2)].

print

Converts the print statement to the print() function.

raise

Converts raise E, V to raise E(V), and raise E, V, T to raise E(V).with_traceback(T). If E is a tuple, the translation will be incorrect because substituting tuples for exceptions has been removed in 3.0.

raw_input

Converts raw_input() to input().

reduce

Handles the move of reduce() to functools.reduce().

reload

Converts reload() to importlib.reload().

renames

Changes sys.maxint to sys.maxsize.

repr

Replaces backtick repr with the repr() function.

set_literal

Replaces use of the set constructor with set literals. This fixer is optional.

standarderror

Renames StandardError to Exception.

sys_exc

Changes the deprecated sys.exc_value, sys.exc_type, sys.exc_traceback to use sys.exc_info().

throw

Fixes the API change in generator’s throw() method.

tuple_params

Removes implicit tuple parameter unpacking. This fixer inserts temporary variables.

types

Fixes code broken from the removal of some members in the types module.

unicode

Renames unicode to str.

urllib

Handles the rename of urllib and urllib2 to the urllib package.

ws_comma

Removes excess whitespace from comma separated items. This fixer is optional.

xrange

Renames xrange() to range() and wraps existing range() calls with list.

xreadlines

Changes for x in file.xreadlines() to for x in file.

zip

Wraps zip() usage in a list call. This is disabled when from future_builtins import zip appears.

sorted

Wraps the argument cmp() in sorted() by :function:`functools.cmp_to_key` and pass it to sorted() through the key() argument.