Write a calculator method using python regular expressions

#!/usr/bin/evnpython
import re
def deal_negative_issue(calc_list):
new_calc_list =[] #Define a new empty list, and then put the data into the new list after filtering is completed
forindex,item in enumerate(calc_list):
ifitem.strip().endswith("*") or item.strip().endswith("/"): #Select thestring ending with a multiplication sign or division sign
NEW_CALC_LIST.APEND ("%S-%S"%(CALC_LIST [Index], CALC_LIST [Index+1])) "*" or "/") in item: #Find the options with multiplication and division in the list. I tried this way of writing and it seems that it only matches *, but 40/5 alone cannot match
elif ("/ ") in item or ("*") in item:

print(item)new_calc_list.append(item)

print("new_calc_ist",new_calc_list)

returnnew_calc_list
def deal_unusual_issue(formula):
formula = formula.replace("++","+")
formula = formula.replace(" +-", "-")
formula = formula.replace("-+", "-")
formula = formula.replace("--", "+")
formula = formula .replace("- -", "+")
return formula

# def addition_and_subtraction(formula):
# sub_calc_list = re.split("[+-]",formula)
# sub_operator_list = re.findall("[+-]",formula)
# print(type(sub_calc_list), sub_operator_list)
# totle_res = None
# for index,i in enumerate(sub_calc_list ):
# ‐ ’ s ’ s ’s ’ s ’ s ’ s ’ s ’ s to t 1-- t t t t t t t to t o t t h e s t o f totle_res: #sub_res is true, indicating that this is not the first time
Loop# Determine whether it is plus or subtraction
# Totle_res+=
Float(i)
Else:TOTLE_RES-= Float (i)









## else:
# sub_res use with using out out out out through out off ‐ ‐ ‐ ‐ ‐ ‐ , use using using using through out out through out out through out through through off ‐ ‐ ‐ ‐ ‐ ‐ and ‐ to to calc_list = re.split("[+-]",formula) #Separate each multiplication and division operation by +- sign
calc_list = deal_negative_issue(calc_list)
print(calc_list)
for item in calc_list:
sub_calc_list = re.split("[*/]",item)
sub_operator_list = re.findall("[*/]",item) #Separate the multiplication and division signs in a list
print (sub_calc_list,sub_operator_list)
sub_res = None
for index,i in enumerate(sub_calc_list):### if sub_res: #sub_res is true, indicating that this is not the first cycle###if sub_operator_list[index-1]=="*": #Determine whether it is addition or subtraction based on the index in sub_operator_list,
sub_res /= float(i )
out ’ way way way ‐ ‐ ‐ ‐ and ‐ ‐ ‐ ‐ to ‐ ‐ ‐ ‐ res ‐ ‐ res ‐ ‐ ‐ res ‐ ‐ res ‐ ‐ res ‐ ‐ res ‐ ‐ ‐ )
formula = deal_unusual_issue(formula)
print(formula)

totle_calc_list = re.split("[+-]", formula)
totle_operator_list = re.findall("[+-]", formula) # Separate the multiplication and division signs in a list
print(totle_calc_list, totle_operator_list)
totle_res = None
for index, item in enumerate( totle_calc_list):
if totle_res: #sub_res is true, indicating that this is not the first cycle
if totle_operator_list[index-1]=="+": #Determine whether it is addition or subtraction through the index in sub_operator_list.
totle_res += float(item)
totle_res -= float(item)
else:
totle_res=float (item)
# return formula
print( "[result]=", totle_res)
return totle_res

def calc(formula):
parentheses_flag = True
calc_res = None

while
parentheses_flag:
m = re.search("\([^()]*\)",formula) #Find the bottom brackets, one by one
print(m)
if m:
#Print (type (m.group ()))
Subformula = m.group (). Strip ("()")#Dip out the found brackets
Subres = Calculating (Subformula)formula = formula.replace(m.group(),str(subres))else:
print("No brackets")
print("The final result is",calculating(formula))
parentheses_flag = False

if name == '
main
':
res = calc("1 - 2 * ( (60-30 +(9-2*5/ -3 + 7 /3*99/4*2998 +10 * 568/14 ) * (40/5)) - (4*3)/ (16-3*2) )")
#res = calc ("2 * (40/5)")

#Note: -40/5 function is not implemented

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