Migrate codebase from Python 2 to Python 3

[Copilot]

BBChop was written for Python 2, which reached end-of-life in 2020. This migration enables the tool to run on modern Python 3 interpreters.

Core Changes

Syntax modernization:

• print statements → print() functions
• raw_input() → input()
• String exceptions → proper Exception classes

Built-in changes:

• xrange() → range() (with list(range()) where mutability required)
• file() → open()
• dict.has_key(key) → key in dict
• dict.iteritems() → dict.items()

Operators and imports:

• operator.div → operator.truediv
• Integer division / → // where needed
• reduce imported from functools

Attribute changes:

• func.func_name → func.__name__

Example

Before:

print "test %d passed" % i
if d.has_key((i,j)):
    for x in xrange(len(ds)):

After:

print("test %d passed" % i)
if (i,j) in d:
    for x in range(len(ds)):

Testing

The main bbchop script and 4/5 test suites (cseTest, testdag, testDagRead, entropiesTest) pass with Python 3.12.3.

Original prompt

Run

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