Python: Validity of a string of parentheses
Python Class: Exercise-3 with Solution
Write a Python class to find validity of a string of parentheses, '(', ')', '{', '}', '[' and ']. These brackets must be close in the correct order,
for example "()" and "()[]{}" are valid but "[)", "({[)]" and "{{{" are invalid.
Sample Solution:
Python Code:
class py_solution:
def is_valid_parenthese(self, str1):
stack, pchar = [], {"(": ")", "{": "}", "[": "]"}
for parenthese in str1:
if parenthese in pchar:
stack.append(parenthese)
elif len(stack) == 0 or pchar[stack.pop()] != parenthese:
return False
return len(stack) == 0
print(py_solution().is_valid_parenthese("(){}[]"))
print(py_solution().is_valid_parenthese("()[{)}"))
print(py_solution().is_valid_parenthese("()"))
Sample Output:
True False True
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Python: Tips of the Day
The Zip() Function:
>>> students = ('John', 'Mary', 'Mike') >>> ages = (15, 17, 16) >>> scores = (90, 88, 82, 17, 14) >>> for student, age, score in zip(students, ages, scores): ... print(f'{student}, age: {age}, score: {score}') ... John, age: 15, score: 90 Mary, age: 17, score: 88 Mike, age: 16, score: 82 >>> zipped = zip(students, ages, scores) >>> a, b, c = zip(*zipped) >>> print(b) (15, 17, 16)
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