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[pre-commit.ci] auto fixes from pre-commit.com hooks

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pre-commit-ci[bot] 2023-05-30 09:31:16 +00:00
parent 5bbcee5c0d
commit b4565e0f60
1 changed files with 44 additions and 15 deletions
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59
data_structures/stacks/postfix_evaluation.py
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@ -68,7 +68,7 @@ def is_operator(data: str) -> bool:
bool
True if data is an operator else False.
"""
if data in ['-', '+', '*', '^', '/']:
if data in ["-", "+", "*", "^", "/"]:
return True
else:
return False
@ -102,7 +102,7 @@ def evaluate(post_fix: list, verbose: bool = False) -> int:
"""
stack = []
opr = {
"^": lambda p, q: p ** q,
"^": lambda p, q: p**q,
"*": lambda p, q: p * q,
"/": lambda p, q: p / q,
"+": lambda p, q: p + q,
@ -120,39 +120,64 @@ def evaluate(post_fix: list, verbose: bool = False) -> int:
stack.append(x) # append x to stack
if verbose:
# output in tabular format
print(str(x).rjust(8), ("push(" + str(x) + ")").ljust(12), stack, sep=" | ")
print(
str(x).rjust(8),
("push(" + str(x) + ")").ljust(12),
stack,
sep=" | ",
)
elif is_operator(x):
# If only 1 value is inside stack and + or - is encountered, then this is unary + or - case
if x in ['-', '+'] and len(stack) < 2:
if x in ["-", "+"] and len(stack) < 2:
b = stack.pop() # pop stack
if x == '-':
if x == "-":
stack.append(-b) # negate b and push again into stack
else: # when x is unary +
stack.append(b)
if verbose:
# output in tabular format
print("".rjust(8), ("pop(" + str(b) + ")").ljust(12), stack, sep=" | ")
print(str(x).rjust(8), ("push(" + str(x) + str(b) + ")").ljust(12), stack, sep=" | ")
print(
"".rjust(8), ("pop(" + str(b) + ")").ljust(12), stack, sep=" | "
)
print(
str(x).rjust(8),
("push(" + str(x) + str(b) + ")").ljust(12),
stack,
sep=" | ",
)
else:
b = stack.pop() # pop stack
if verbose:
# output in tabular format
print("".rjust(8), ("pop(" + str(b) + ")").ljust(12), stack, sep=" | ")
print(
"".rjust(8), ("pop(" + str(b) + ")").ljust(12), stack, sep=" | "
)
a = stack.pop() # pop stack
if verbose:
# output in tabular format
print("".rjust(8), ("pop(" + str(a) + ")").ljust(12), stack, sep=" | ")
print(
"".rjust(8), ("pop(" + str(a) + ")").ljust(12), stack, sep=" | "
)
stack.append(opr[x](a, b)) # evaluate the 2 values popped from stack & push result to stack
stack.append(
opr[x](a, b)
) # evaluate the 2 values popped from stack & push result to stack
if verbose:
# output in tabular format
print(str(x).rjust(8), ("push(" + str(a) + str(x) + str(b) + ")").ljust(12), stack, sep=" | ")
print(
str(x).rjust(8),
("push(" + str(a) + str(x) + str(b) + ")").ljust(12),
stack,
sep=" | ",
)
else:
print(f"{x} is neither a number, nor a valid operator")
break
if len(stack) == 1: # If everything executed correctly, the stack will contain only one element which is the result
if (
len(stack) == 1
): # If everything executed correctly, the stack will contain only one element which is the result
_, result = get_number(stack[0])
else:
result = None
@ -174,7 +199,7 @@ def is_yes(val: str) -> bool:
bool
True if Yes, otherwise False
"""
if val in ['Y', 'y']:
if val in ["Y", "y"]:
return True
else:
return False
@ -182,8 +207,12 @@ def is_yes(val: str) -> bool:
if __name__ == "__main__":
loop = True
while loop: # Creating a loop so that user can evaluate postfix expression multiple times
expression = input("Enter a Postfix Equation (space separated) For Example: 5 6 9 * +\n: ").split(" ")
while (
loop
): # Creating a loop so that user can evaluate postfix expression multiple times
expression = input(
"Enter a Postfix Equation (space separated) For Example: 5 6 9 * +\n: "
).split(" ")
choice = input("Do you want to see stack contents while evaluating? [y/N]: ")
display = is_yes(choice)
output = evaluate(expression, display)