Cheks if input file has balanced parentheses. Returns 'Well parenthesed' or 'Bad parenthesed'.
'Well parenthesed' condition:
- there is as many open par. as closing par.;
- any prefix text contains at least as many opening par. as closing;
- no closing parenthesis of one kind followed an opening parenthesis of another kind.
def parentheses_checker1(file):
"""
Returns the phrase 'Well parenthesed' if each open parenthesis has
the matching close one.
In the opposite case, returns the phrase 'Bad parenthesed'.
:param file: file ( .txt, .py, etc.)
:return: 'Well parenthesed'/'Bad parenthesed'
:rtype: str
:UC: file is an external file
:example:
>>> parentheses_checker1('stack.py')
'Well parenthesed'
>>> parentheses_checker1('bad_stack1.py')
'Bad parenthesed'
>>> parentheses_checker1('bad_stack3.py')
'Bad parenthesed'
"""
with open(file) as f:
strInput = f.read()
if strInput:
brackets = [ ('(',')'), ('[',']'), ('{','}')]
kStart = 0
kEnd = 1
stck=stack.create()
for char in strInput:
for bracketPair in brackets:
if char == bracketPair[kStart]:
stck.append(char)
elif char == bracketPair[kEnd] and len(stck) > 0 and stck.pop() != bracketPair[kStart]:
return 'Bad parenthesed'
if len(stck) == 0:
return 'Well parenthesed'
return 'Bad parenthesed'Returns line, column and reason of unbalanced parenthesis.
class ParenthesisError(Exception):
def __init__(self, parenthesis, error):
what_is_wrong = '%s at line %s, char number %s, the problem is >>> %s'
parenthesis.line = parenthesis.line.replace('\n', '\\n')
self.what_is_wrong = what_is_wrong % (error ,parenthesis.i_line-1, parenthesis.i_char-1, parenthesis.line)
def __str__(self):
return self.what_is_wrong
class Parenthesis:
def __init__(self, i_line, line, i_char):
self.i_line = i_line
self.line = line
self.i_char = i_char
def parentheses_checker2(filename):
"""
Returns the line, char number and phase containing unbalanced
parentheses is there's parenthesis problem.
In the opposite case, returns nothing.
:param file: file ( .txt, .py, etc.)
:return: None or line, char number and phase
:rtype: str or None
:UC: file is an external file
:example:
>>> parentheses_checker2('stack.py')
>>> parentheses_checker2('bad_stack2.py')
Wrong open parenthesis at line 80, char number 13, the problem is: >>> def is_empty (s:\n
>>> parentheses_checker2('bad_stack3.py')
Wrong open parenthesis at line 10, char number 2, the problem is: >>> A [ module for stack data structure.\n
"""
par_open = {'(':[], '[':[], '{':[]}
par_close = {')':'(', ']':'[', '}':'{'}
with open(filename) as f:
for i_line, line in enumerate(f, start=1):
for i_char, char in enumerate(line, start=1):
if char in par_open:
par_open[char].append(Parenthesis(i_line=i_line, line=line, i_char=i_char))
elif char in par_close:
try:
par_open[par_close[char]].pop()
except IndexError:
print(ParenthesisError(Parenthesis(i_line=i_line, line=line, i_char=i_char), 'Wrong closed parenthesis '))
for _, l in par_open.items():
for parenthesis in l:
print(ParenthesisError(parenthesis, 'Wrong open parenthesis'))