Pipe output from shell command to a python script

Question

I want to run a mysql command and set the output of that to be a variable in my python script.

Here is the shell command I'm trying to run:

$ mysql my_database --html -e "select * from limbs" | ./script.py 

Here is the python script:

#!/usr/bin/env python  import sys  def hello(variable):     print variable 

How would I accept the variable in the python script and have it print the output?

Answer 1

You need to read from stdin to retrieve the data in the python script e.g.

#!/usr/bin/env python  import sys  def hello(variable):     print variable  data = sys.stdin.read() hello(data) 

If all you want to do here is grab some data from a mysql database and then manipulate it with Python I would skip piping it into the script and just use the Python MySql module to do the SQL query.

Answer 2

If you want your script to behave like many unix command line tools and accept a pipe or a filename as first argument, you can use the following:

#!/usr/bin/env python import sys  # use stdin if it's full                                                         if not sys.stdin.isatty():     input_stream = sys.stdin  # otherwise, read the given filename                                             else:     try:         input_filename = sys.argv[1]     except IndexError:         message = 'need filename as first argument if stdin is not full'         raise IndexError(message)     else:         input_stream = open(input_filename, 'rU')  for line in input_stream:     print(line) # do something useful with each line