CODEWITHSUNDEEP
pythonif-statement
jms1980
jms1980

Reputation: 1075

if then statements with sys.argv in python

I am trying to do a python script where I enter a argument into the command line. The program is temperature.py so if I enter:

./temperature.py 56

sys.argv[1] = 56

Now the program is as such:

import sys

temp=sys.argv[1]
print temp

if temp < 65:
    print "Temperature is Cold"
else:
    print "Temperature is warm"

based on the above logic I would expect that if I entered in the prompt

./temperature.py 56

temp would be 56 which is less than 65, so I could have a response:

"Temperature is Cold"

but I get the response:

"Temperature is Warm"

no matter what temperature I put in the argument. I still get the correct temp value that equals what the first argument is correct (56) so I am at a loss as to why the logic is malfunctioning in the if then statement. How do I get the logic to work so that when I enter a temperature less than 65 (i.e. ./temperature.py 56) I get the response "Temperature is Cold" and if I enter a temperature greater than 65 (i.e. ./temperature.py 75), I would get the response temperature is warm? Any ideas?

Upvotes: 0

Views: 1166

Answers (1)

Adam Smith
Adam Smith

Reputation: 54163

Arguments are strings, not integers. You're comparing "56" < 65 which is False. Instead try:

# temperature.py
import sys

try:
    temperature = float(sys.argv[1])
except ValueError:
    print("Argument must be a number")
    sys.exit(1)
    # kick out with an error code

if temp < 65:
    # etc as you have it

Upvotes: 2

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