Problem 1

def remove_duplicates(l):
    result = []
    for i in l:
        if not i in result:
            result.append(i)
    return result

remove_duplicates([3, 2, 1, [3], 2, [3], 5, 5, 5])

[3, 2, 1, [3], 5]

Problem 2

@interact
def interact_print_table(f, ls):
    if not f or not ls:
        return
    print_table(f, ls)
    
#specify function and list below after evaluating this cell

f
ls

[removed]

[removed]

[removed]

Problem 4

My solution doesn't work in Sage. Change the type of the worksheet above to python before evaluating this problem, or run the file included in the email.

# DOESN'T WORK IN SAGE!
def square_cube_prover(n):
    sum_to_square = 0
    cubed_sum = 0
    for i in xrange(1, n+1):
        sum_to_square += i
        cubed_sum += i**3
        square = sum_to_square**2
        if not square == cubed_sum:
            print "OH NO! (1 + ... + %i)^2 = %i; 1^3 + ... + %i^3 = %i!" % (i, square, i, cubed_sum)
            return
        if i % (n/10) == 0:
            # print progress every 10% of the way through
            print "True for 1 through %i" % (i)

square_cube_prover(2000)

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "_sage_input_8.py", line 9, in <module>
    exec compile(ur'open("___code___.py","w").write("# -*- coding: utf-8 -*-\n" + _support_.preparse_worksheet_cell(base64.b64decode("c3F1YXJlX2N1YmVfcHJvdmVyKDIwMDAp"),globals())+"\n"); execfile(os.path.abspath("___code___.py"))' + '\n', '', 'single')
  File "", line 1, in <module>
    
  File "/tmp/tmpc3EGFg/___code___.py", line 3, in <module>
    exec compile(ur'square_cube_prover(_sage_const_2000 )' + '\n', '', 'single')
  File "", line 1, in <module>
    
  File "/tmp/tmpG7iPOB/___code___.py", line 13, in square_cube_prover
    if i % (n/_sage_const_10 ) == _sage_const_0 :
  File "rational.pyx", line 2290, in sage.rings.rational.Rational.__mod__ (sage/rings/rational.c:16853)
TypeError: Argument 'self' has incorrect type (expected sage.rings.rational.Rational, got int)

Problem 5

To test that the contents of the log file are right, I'd just run the file included in the email.

class file_logger(object):
	
	def __init__(self, filename):
		self.__log = open(filename, "a")
		
	def __call__(self, f):
		def g(*args, **kwds):
			input = "args = %s; kwds = %s" % (repr(*args or None), str(**kwds))
			output = repr(f(*args, **kwds))
			self.__log.write("function: %s\ninput:\n%s\noutput:\n%s\n\n" % (f.__name__, input, output))
			self.__log.flush()
		return g

my_logger = file_logger("test_log.txt")

@my_logger
def f(input):
	return "THIS IS MY OUTPUT FOR INPUT '%s'" % str(input)