Check 9.1
Write the function combineStrings(lst), which takes a list of strings, lst, and returns a single string with all of lst's strings combined in order. You must solve this problem recursively- do not use loops, comprehensions, or join.
def combineStrings(lst):
pass
def testCombineStrings():
print("Testing combineStrings()...", end="")
assert(combineStrings(["a", "b", "c"]) == "abc")
assert(combineStrings(["foo"]) == "foo")
assert(combineStrings([]) == "")
print("Done.")
testCombineStrings()
import sys
def set_certificate(certificate_div_id, certificate):
document[certificate_div_id].textContent = certificate
def get_student_code(student_code_div_id):
raw_student_code = document[student_code_div_id].textContent
return window.patchCodeToCheckTimeout(raw_student_code, 'check_timeout();');
class captureIO:
def __init__(self):
self.captured = []
def get_output(self):
out = ""
for c in self.captured:
out += str(c)
return out
def write(self, data):
self.captured.append(data)
def flush(self):
pass
test_rec = """
certificate = []
def inject_counters():
def callCounter(f):
f.calls = 0
f.is_recursive = False
def g(*args):
f.calls += 1
initial_calls = f.calls
out = f(*args)
if (f.calls > initial_calls):
f.is_recursive = True
return out
return g, f
g = globals()
current_objects = list(g.items())
originals = []
for name, obj in current_objects:
try:
if callable(obj):
g[name], original = callCounter(obj)
originals.append(original)
except:
pass
return originals
def did_recur(originals):
return any(map(lambda f: f.is_recursive, originals))
originals = inject_counters()
combineStrings(["a", "b", "c"])
recurs = did_recur(originals)"""
def make_certificate(student_code_div_id, certificate_div_id):
student_code = get_student_code(student_code_div_id)
try:
execCapture = captureIO()
sys.stdout = execCapture
sys.stderr = execCapture
exec(student_code+"\n"+test_rec, globals())
if recurs:
tests = [['Y', 'L', 'W', 'I', '=%p~)W', 'n'], ['c:', ''], ['\\7', '8#Y\x0bapC'], ['', 'mJ#yHf[UU', ',e_s'], ['K(+Jqi'], ['=g', 'C4lq', 'N', '', 'J'], ['wts', '7vXGU\x0b', '', '1', '', ''], ['', '', '', 'Q=RVRg;}.', 'w-', "'\\:", 'f&S4&', 'ds'], ['i&b2', '', 'x', 'u{qAW', 'a', '70K\t'], ['nMc%', '', 'f', '', '-k', 'kb=tGO&D', ''], ['x\\', 'vtz>'], ['_', '', 'Co6#%y>e', '$q', '%{', '20k\t,']]
test1 = ["a", "b", "c"]
test2, test3 = ['foo'], []
tests.extend([test1, test2, test3])
for test in tests:
output = combineStrings(test)
certificate.append((output, type(output)))
set_certificate(certificate_div_id, str(certificate))
else: set_certificate(certificate_div_id, "Not Recursive")
except:
set_certificate(certificate_div_id, "error")