notes-passing_args.txt

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| November 16th, 2016               |
|  Passing Arguments into a script  |
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# Making a script executable without calling python first, place
# the below 'shebang' at the top of the file: (include the #)
#!/usr/bin/env python

# Use 'input' to call a library. 
#  A library for accepting arguments such as input is 'sys'
import sys

# Simple statement to print arguments passed to the script. This returns a list.
print sys.argv
$ ./script.py whatever another things
['./temp.py', 'whatever', 'another', 'things']

# Accepting input with some decisionmaking:
 #!/usr/bin/env python

 import sys

 if len(sys.argv) == 2:
   ip_addr = sys.argv.pop()
   print("The IP address is {}".format(ip_addr))
 else:
   print("You made an error.")

 $ ./temp.py 10.1.1.1
 The IP address is 10.1.1.1
 $ ./temp.py 10.1.1.1 120.1.1.1
 You made an error.
 $ ./temp.py 10.1.1.1 120.1.1.1 1.1.1.1
 You made an error.