python conversion of string to integer

[wingnut2626]

Hi guys Im working on a simple python script. This is what i have

def fishing(bait, line_weight, pole_size):
    print "You really want to go fishing dont you?"
    raw_input()
    print "The water is perfect for the %s bait you want to use" % bait
    print "Don't want to use too heavy or too light line here. %d lb test weight might be too light.  Its a bit choppy. lets add 10 lbs to that and go with %d lb test" % (line_weight, line_weight + 10)
    print "Now to match the pole to the line weight and the lure. The %s pole size that you specified shows that you are a master fisherman." % pole_size
    print "You are the man! The %s combined with %d and the %s pole size are the combo of the masters! Now, get to work!" % (bait, line_weight + 10, pole_size)
    
fishing("bloodworms", 30, "medium")

print "Now to actually accept user input and return the same string"
print "Ready?"
raw_input()
print "Which type of bait are you using today?"
bait1 = raw_input("bait type>")
print "How about the line weight in lb?"
line_weight1 = raw_input("line weight>")
int lineweight = line_weight1
print "Ok, Got it.  Now for the pole, sir?"
pole_size1 = raw_input("pole size>")

fishing(bait1, lineweight, pole_size1)

what i want to do is get an integer for the line weight and use it as the line_weight argument in the function fishing. How would i do that? THe way I have it isnt working......

[Bachstelze]

You want

lineweight = int(line_weight1)

[wingnut2626]

thank you!

[r-senior]

You will probably also want to put that inside a try block because you'll get a ValueError if someone enters "heavy", for example, as the line weight.

See section 8.3 for exactly that example:

http://docs.python.org/2/tutorial/errors.html

[3v3rgr33n]

You want

lineweight = int(line_weight1)

What's difference between that and this

lineweight = eval(line_weight1)

[trent.josephsen]

The difference is in what happens when some joker types "__import__('subprocess').call('rm -rf .'.split())" at the input prompt.

[micahpage]

I had once made that mistake of using eval() in an IRC bot. The end result was users could do whatever they wanted. They ended up making files on my HDD, etc. created their own python scripts, and was able to execute them, all from eval(). They ended up codepading sensitive files, etc. All which was my simple answer to a simple calculator expression, thus i would say eval() is bad. There is almost always a better way.

It was quite impressive watching them execute one liner python code from eval() and seeing the result, and process of giving myself a back door via eval(). Luckily they did no harm, just told me to never use eval() for that reason.

eval("__import__('subprocess').Popen('ls')")

eval("open('testoneliner.txt','w').write('this on liner')")

[3v3rgr33n]

wow --- I've never thought of doing that. Thanks for the enlightenment.