I had to a make a python function to be a single line calculator and we have to add exponents in along with a stack to do other operations like parentheses and negatives. Refer to pdfs for full assignment.This is due this Friday, July 13, 2018.

class Node:

def __init__(self, value):

self.value = value

self.next = None

def __str__(self):

return "Node({})".format(self.value)

__repr__ = __str__

class Stack:

def __init__(self):

self.head = None

self.tail = None

self.count = 0

def __str__(self):

temp = self.head

out = ''

while temp:

out += str(temp.value)+ ' '

temp = temp.next

return ('Head:{} Tail:{} List:{}'.format(self.head,self.tail,out))

__repr__=__str__

def add(self, value):

addN = Node(value)

if self.head is None:

self.head = addN

self.tail = addN

self.count += 1

return

elif self.head.value >= addN.value:

addN.next = self.head

self.head = addN

else:

cur = self.head

while(cur.next is not None and

cur.next.value

cur = cur.next

addN.next = cur.next

cur.next = addN

self.count += 1

temp = self.head

while(temp.next is not None):

temp = temp.next

self.tail = temp

def pop(self):

value_P = ''

if self.isEmpty():

return 'List is Empty'

if self.head.next == None:

value_P = self.head.value

self.head = None

self.tail = None

self.count -= 1

return value_P

temp1 = self.head

temp2 = None

while temp1.next is not None:

temp2 = temp1

temp1 = temp1.next

value_P = temp1.value

self.count -= 1

temp2.next = None

self.tail = temp2

return value_P

def isEmpty(self):

if self.head == None:

return True

else:

return False

def size(self):

count = 0

Cnode = self.head

while Cnode is not None:

count = count + 1

Cnode = Cnode.next

return count

def findNextOpr(txt):

if len(txt)

print("type mimatch error: findNextOpr")

return -1

elif txt.find("+") != -1 or txt.find("-") != -1 or txt.find("*") != -1 or txt.find("/") != -1 or txt.find("^") != -1:

for i in range(len(txt)):

index_val = txt[i]

if(index_val == "+" or index_val == "-" or index_val == "*" or index_val == "/" or index_val == "^"):

return i

break

else:

return -1

def isNumber(txt):

if len(txt) == 0 or not isinstance(txt, str):

print("type mismatch error: isNumber")

return False

else:

if txt[0] == "-":

txt = txt[1:]

try:

float(txt)

return True

except ValueError:

return False

def getNextNumber(expr, pos):

if len(expr) == 0 or not isinstance(expr, str) or pos len(expr) or not isinstance(pos, int):

return None, None, "type mismatch error: getNextNumber"

else:

next_num = None

next_opr = None

nex_opr_pos = None

nex_opr_pos = findNextOpr(expr[pos:])

if nex_opr_pos > 0:

nex_opr_pos += pos

next_opr = expr[nex_opr_pos]

if isNumber(expr[pos:nex_opr_pos]):

next_num = float(expr[pos:nex_opr_pos])

else:

next_opr = None

if isNumber(expr[pos:]):

next_num = float(expr[pos:])

return next_num, next_opr, nex_opr_pos

def exeOpr(num1, opr, num2):

#This funtion is just an utility function. It is skipping type check

if opr=="+":

return num1+num2

elif opr=="-":

return num1-num2

elif opr=="*":

return num1*num2

elif opr=="/":

if num2==0:

print("Zero division error")

return "Zero division error"

else:

return num1um2

elif opr=="^":

return num1 ** num2

else:

print("error in exeOpr")

return "error in exeOpr"

def _calculator(expr):

pos = 0

posi = 1

next_opr = 0

result = 0

mode_change = None

addlastOpr = None

mullastOpr = None

explastOpr = None

if not isinstance(expr,str) or len(expr)

return "argument error: line A in eval_expr"

expr = expr.strip()

if expr[0]!="-":

newNumber, newOpr, oprPos = getNextNumber(expr, 0)

else:

newNumber, newOpr, oprPos = getNextNumber(expr, 1)

newNumber *= -1

if newNumber is None:

return "input formula error: line B in eval_expr"

elif newOpr is None:

return newNumber

elif newOpr == "+" or newOpr == "-":

mode = "add"

addResult = newNumber

mulResult = 1

expResult = 0

addlastOpr=newOpr

elif newOpr == "*" or newOpr == "/":

mode = "mul"

addResult = 0

mulResult = newNumber

expResult = 0

mullastOpr = newOpr

elif newOpr=="^":

mode="exp"

addResult=0

mulResult=1

addLastOpr="+"

mulLastOpr="*"

expNumber=newNumber

while True:

newNumber, newOpr, oprPos = getNextNumber(expr, oprPos + 1)

if newNumber is None:

return "input formula error: line B in eval_expr"

elif newOpr is None and mode=="add":

return exeOpr(addResult, addlastOpr, newNumber)

elif newOpr is None and mode =="mul":

mulResult=exeOpr(mulResult,mullastOpr,newNumber)

return exeOpr(addResult, addlastOpr, mulResult)

elif newOpr is None and mode=="exp":

expResult = exeOpr(expNumber, explastOpr, newNumber)

mulResult = exeOpr(mulResult, mulLastOpr, expResult)

return exeOpr(addResult, addLastOpr, mulResult)

elif (newOpr=="+" or newOpr=="-") and mode=="exp":

expResult = exeOpr(expNumber, newOpr, newNumber)

mulResult = exeOpr(mulResult, mulLastOpr, expResult)

addResult = exeOpr(addResult, addLastOpr, mulResult)

mode="add"

elif (newOpr=="*" or newOpr=="/") and mode=="exp":

expResult = exeOpr(expNumber, newOpr, newNumber)

mulResult = exeOpr(mulResult, mulLastOpr, expResult)

mode = "mul"

elif (newOpr == "+" or newOpr =="-") and mode == "add":

addResult=exeOpr(addResult, addlastOpr, newNumber)

addlastOpr=newOpr

mode = "add"

elif (newOpr == "*" or newOpr == "/") and mode == "add":

mulResult=newNumber

mullastOpr = newOpr

mode="mul"

elif newOpr=="^" and mode=="add":

addLastOpr = newOpr

mulResult = 1

mulLastOpr = "*"

expNumber= newNumber

mode = "exp"

elif (newOpr == "+" or newOpr == "-") and mode == "mul":

mulResult=exeOpr(mulResult,mullastOpr, newNumber)

if addlastOpr is None:

addResult= mulResult

else:

addResult=exeOpr(addResult, addlastOpr, mulResult)

addlastOpr=newOpr

mode="add"

elif (newOpr == "*" or newOpr=="/") and mode == "mul":

mulResult=exeOpr(mulResult, newOpr, newNumber)

mode="mul"

mullastOpr=newOpr

elif (newOpr == "^") and mode == "mul":

mode = "exp"

expResult=newNumber

explastOpr = newOpr

def calculator(expr):

# Required: calculator must create and use a Stack for parenthesis matching

# Call _calculator to compute the inside parentheses

if len(expr)

print("argument error: calculator")

return "argument error: calculator"

expr = expr.strip()

s = Stack() # You must use the Stack s

pos = expr.find("(")

while True:

#--- function code starts here -----#

#--- function code ends here-----#

CNMPSC-122: Intermediate Programming Summer 2018 Homework 2 Due Date: 06/22/2018, 11:59PMEST 100 pts Instructions: The work in this assignment st be completed alone. The file name nust be HW2.py (incorrect name files will get a -10 point deduction) When any function returns an error, it nust be a string containing "error" Do not include test code outside any function in the upload. Remove all your testing code before uploading your file. That inchudes user-defined inputO Goal Modify the function calculator(expr) so that t supports exponentiation This operation will be represented in the string as ^unlike Python's **. In this assignment, more than one consecutive exponentiation is not supported. An example ofa valid expression is -5 60/3A3 * 4 2* 42" Notes This is a straightforward upgrade of HW1 and there is no starter code You will also have to modify findNextOpr and exeOpr to include (which is* in Python) In your submission include all functions in your HW2 py script (calculator, findNextOpr isNumber, getNextNumber and exeOpr) Function requirements: The function must return the computed value if expr is a correct formula, otherwise it must retun an error message When any function returns a numeric value, it ust be float Do not use exec or eval function, You will not receive credit if All five functions from HW1 nust work Grading Notes: your program uses any of the two functions anyw here The grading script will feed 5 randomly chosen test inputs, each for 20 points. One of them will be an input that should cause an error such as "4 * / 2 + 5 ^, whose expected returned value is an error message. Example: calculator("-5 + 60 / 3"3 4-2 * 4"2") >>> calculator ("42/22") >>> calculator ("-4 /22") error Deliverables: Include all the functions in your script named HW2 py. Submit it to the HW2 CANVAS assignment before the due date