def do_del(self, line):
'''Delete variables.'''
if self.variables:
patterns = line.split()
if len(patterns) == 0:
self.variables.clear()
print('Deleted all variables.')
else:
names = sorted(self.variables.keys(), key=lambda s: s.lower())
deleted = []
try:
for pattern in patterns:
regex = compile('^' + pattern + '$')
for name in names:
if regex.match(name) and name in self.variables:
del self.variables[name]
deleted.append(name)
except Exception:
# Catches re's "nothing to repeat" errors
# This happens, for example, for "del *"
# What is a more specific exception in this case?
print('Runtime error: Invalid pattern:', pattern)
if deleted:
print_iterable(chain(['Delteted:'], deleted))
else:
print('No variables matched the given pattern' +
int(bool(patterns[1:])) * 's' + '.')
else:
print('There are no variables to delete.')
def default(self, line):
'''Evaluate the given expression.'''
try:
self.parser.parse(line)
self.names = self.parser.names
tree = self.parser.tree
if tree.set_vars(self.variables) or tree.set_vars(constants):
self.value = tree.evaluate()
for name in self.names:
self.variables[name] = self.value
else:
raise Exception('Encountered unknown variable.')
print_iterable(self.names, sep=', ', end=' =\n')
print(' ' + str(self.value))
except ParseException as ex:
print('Runtime error:', str(ex))
underline_substring(ex.expression, ex.start, ex.end)
except KeyboardInterrupt:
print('\nInterrupted.')
except Exception as ex:
print('Runtime error:', str(ex))