通过命令行运行此python程序

Question

I need to run this python program through my command line, but im not sure how to do so. You're supposed to modify the PATH environment variables before you can do this, correct? I'm using python 3.5 if that helps.

from sys import argv

DEFAULT_KEY = 3

def main() :
   key = DEFAULT_KEY
   inFile = ""
   outFile = ""

   files = 0   # Number of command line arguments that are files.
   for i in range(1, len(argv)) :
      arg = argv[i]
      if arg[0] == "-" :
         # It is a command line option.
         option = arg[1]
         if option == "d" :
            key = -key
         else :
            usage()
            return

      else :
         # It is a file name
         files = files + 1
         if files == 1 :
            inFile = arg
         elif files == 2 :
            outFile = arg

   # There must be two files.
   if files != 2 :
      usage() 
      return 

   # Open the files.
   inputFile = open(inFile, "r")
   outputFile = open(outFile, "w")

   # Read the characters from the file.
   for line in inputFile :
      for char in line :
         newChar = encrypt(char, key)
         outputFile.write(newChar)

   # Close the files.
   inputFile.close()
   outputFile.close()

## Encrypts upper- and lowercase characters by shifting them according to a key.
#  @param ch the letter to be encrypted
#  @param key the encryption key
#  @return the encrypted letter      
#
def encrypt(ch, key) :
   LETTERS = 26   # Number of letters in the Roman alphabet.

   if ch >= "A" and ch <= "Z" :
      base = ord("A")
   elif ch >= "a" and ch <= "z" :
      base = ord("a")
   else :
      return ch    # Not a letter.

   offset = ord(ch) - base + key
   if offset > LETTERS :
      offset = offset - LETTERS
   elif offset < 0 :
      offset = offset + LETTERS 

   return chr(base + offset)

## Prints a message describing proper usage.
#
def usage() :
   print("Usage: python cipher.py [-d] infile outfile")

# Start the program.
main()

Answer 1

Have you tried ...

C:>python code.py arguments

Check this link to know about setting path variables if the above fails. How to add to the pythonpath in windows 7?

Answer 2

If you saved the program as cipher.py Run the program

python cipher.py infile outfile.json

Check outfile.json is created...