[@outsidetried ~]$ python validate_json_adj.py 
[@outsidetried ~]$ python validate_json_adj.py -h
validate_json.py -i <input_file>
[@outsidetried ~]$ python validate_json_adj.py -i hello.txt
Input JSON file provided for verification: hello.txt
[@outsidetried ~]$ python validate_json_adj.py -i firstfile
Input JSON file provided for verification: firstfile
[@outsidetried ~]$ python validate_json_adj.py -i <hello.txt>
-bash: syntax error near unexpected token `newline'
[sureshgv@outsidetried ~]$ python validate_json_adj.py -i ??
Input JSON file provided for verification: ci
[@outsidetried ~]$ python validate_json_adj.py -i ???
Input JSON file provided for verification: bf1
[@outsidetried ~]$ python validate_json_adj.py -i $#@%
Input JSON file provided for verification: 0@%
[@outsidetried ~]$ cat validate_json_adj.py 
#!/usr/bin/python
"""
"""

import sys,getopt


"""
 """

def main(argv):
   inputfile = ''
   try:
      opts, args = getopt.getopt(argv,"hi:",["input_file="])
   except getopt.GetoptError:
      print 'validate_json.py -i <input_file>'
      sys.exit(2)
   for opt, arg in opts:
      if opt == '-h':
         print 'validate_json.py -i <input_file>'
         sys.exit()
      elif opt in ("-i", "--input_file"):
         inputfile = arg
   	 print 'Input JSON file provided for verification:', inputfile 
if __name__ == "__main__":
   main(sys.argv[1:])

This is not a problem with python, but rather with how bash interprets your program arguments. Try putting the arguments in single quotes, like:

python validate_json_adj.py -i '$#@%'