Combining print statements with list comprehension in python

Question

I'm writing code to send and receive messages in python using a GSM modem.

Whenever a new message is received I get the following response in a list x after reading from a serial port object.

+CMTI: "SM",0 # Message notification with index

I'm polling for this indication and I've made use of list comprehensions to check whether I have received the above response

def poll(x):
    regex=re.compile("\+CMTI:.......")
    [m for l in x for m in [regex.search(l)] if m]

This seems to be working however I want to add a print statement whenever a match is found like

print "You have received a new message!"

How can I combine the print statement with the above?

Answer 1

With a normal for loop, it can be done like this:

def poll(x):
    regex = re.compile("\+CMTI:.......")
    lst = []
    for l in x:
        for m in [regex.search(l)]:
            if m:
                lst.append(m)
                print "You have received a new message!"

Note that this list isn't being stored anywhere (outside the function scope) - perhaps you want to return it.

---

As a side note, the hacky solution:

from __future__ import print_function
def poll(x):
    regex = re.compile("\+CMTI:.......")
    [(m, print("You have received a new message!"))[0] for l in x for m in [regex.search(l)] if m]

But this is very unpythonic - use the other version instead.