responses=["Welcome to SMART CALCULATOR","My Name is Calci","Thanks","Sorry,this is beyond my ability"]

def extract_numbers_from_text(text):

l=[]

for t in text.split(' '):

try:

l.append(float(t))

except ValueError:

pass

return(l)

def add(a,b):

return a+b

def sub(a,b):

return a-b

def mul(a,b):

return a*b

def div(a,b):

return a/b

def myName():

print(responses[1])

def sorry():

print(responses[3])

def end():

print(responses[2])

input("Press Enter key to exit")

exit()

def help():

print("List of Valid Commands")

for k in operations:

print(k)

for k in commands:

print(k)

#--------------------------------Operations dictionary----------------------------------

operations={

"PLUS":add,"ADD":add,"SUM":add,"ADDITION":add,"+":add,

"MINUS":sub,"SUBTRACT":sub,"SUBTRACTION":sub,"DIFFERENCE":sub,"-":sub,

"MULTIPLY":mul,"PRODUCT":mul,"MULTIPLICATION":mul,"*":mul,

"DIVIDE":div,"DIVISION":div,"/":div

}

#---------------------------------Commands dictionary------------------------------------

commands={

"NAME":myName,

"END":end,

"EXIT":end,

"CLOSE":end,

"EXIT":end,

"HELP":help,

}

#----------------------------------------main()--------------------------------------

def main():

print(responses[0],responses[1],sep='\n')

while True:

print()

text=input("Enter some text: ")

for word in text.split(' '):

if word.upper() in operations.keys():

try:

l=extract_numbers_from_text(text)

r=operations[word.upper()](l[0],l[1])

print(r)

except:

print("Something is wrong,Please retry !!!")

finally:

break

elif word.upper() in commands.keys():

commands[word.upper()]()

break

else:

sorry()

if __name__=="__main__":

main()