The code below shows error if a decimal (eg. 49.9) is sent to next variable. Can you please tell me why? Why does int() converts it into an integer?

next=raw_input("> ")

how_much = int(next)

if how_much < 50:

print"Nice, you're not greedy, you win"

exit(0)

else:

dead("You greedy bastard!")

If I dont use int() or float() and just use:

how_much=next

then it moves to "else" even if I give the input as 49.8.

解決方案

As the other answers have mentioned, the int operation will crash if the string input is not convertible to an int (such as a float or characters). What you can do is use a little helper method to try and interpret the string for you:

def interpret_string(s):

if not isinstance(s, basestring):

return str(s)

if s.isdigit():

return int(s)

try:

return float(s)

except ValueError:

return s

So it will take a string and try to convert it to int, then float, and otherwise return string. This is more just a general example of looking at the convertible types. It would be an error for your value to come back out of that function still being a string, which you would then want to report to the user and ask for new input.

Maybe a variation that returns None if its neither float nor int:

def interpret_string(s):

if not isinstance(s, basestring):

return None

if s.isdigit():

return int(s)

try:

return float(s)

except ValueError:

return None

val=raw_input("> ")

how_much=interpret_string(val)

if how_much is None:

# ask for more input? Error?

總結

以上是生活随笔為你收集整理的python int函数详解,python int（）函数的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。