Files
edx-platform/common/lib/capa/util.py
2012-06-12 13:43:14 -04:00

31 lines
1.0 KiB
Python

from calc import evaluator, UndefinedVariable
#-----------------------------------------------------------------------------
#
# Utility functions used in CAPA responsetypes
def compare_with_tolerance(v1, v2, tol):
''' Compare v1 to v2 with maximum tolerance tol
tol is relative if it ends in %; otherwise, it is absolute
- v1 : student result (number)
- v2 : instructor result (number)
- tol : tolerance (string or number)
'''
relative = tol.endswith('%')
if relative:
tolerance_rel = evaluator(dict(),dict(),tol[:-1]) * 0.01
tolerance = tolerance_rel * max(abs(v1), abs(v2))
else:
tolerance = evaluator(dict(),dict(),tol)
return abs(v1-v2) <= tolerance
def contextualize_text(text, context): # private
''' Takes a string with variables. E.g. $a+$b.
Does a substitution of those variables from the context '''
if not text: return text
for key in sorted(context, lambda x,y:cmp(len(y),len(x))):
text=text.replace('$'+key, str(context[key]))
return text