I have this line in my programme-
num = int(input("Enter a number: "))
Now as the input type is int, I cannot use any exponents. How can I change the data input type from int to something else so that I can input exponents like 2**4 (= 2^4)?
2 Answers
Don't use int() :)
>>> x = input("Enter a number:")
Enter a number:2**3
>>> print x
8
It can be explained by the documentation (https://docs.python.org/2/library/functions.html#input):
input([prompt])Equivalent to
eval(raw_input(prompt)).This function does not catch user errors. If the input is not syntactically valid, a SyntaxError will be raised.
Other exceptions may be raised if there is an error during evaluation....
Consider using the raw_input() function for general input from users.
In python3 things a bit changed, so the following alternative will work:
x = eval(input("Enter a value"))
print(x)
2 Comments
Vadim Key
Of course. That's how input works. Probably you thought about raw_input()?
You could always accept a string and then split in on a delimiter of your choice, either ^ or **.
If I'm not mistaken, eval is insecure and should not be used (please correct me if I'm wrong).
2 Comments
Hassan Mehmood
how insecure, can you explain a bit?
Maorg
consider what will happen on you eval os.system("rm -rf /") . If you'd like to get more information on the matter, please go to: nedbatchelder.com/blog/201206/eval_really_is_dangerous.html Hope this helps, friend.
**.