How can i shorten this python code

Question

I want to shorten this code using some kind of loop: for, if(inside if), while, foreach, or another one.

def FindChannel():
    rc_program_up = "Ch+"
    rc_ok = "ok"
    rc_exit = "exit"
    value0 = checkPicture(15)

    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

I can not do it, please help me.

You could try using `elif`. https://docs.python.org/2/tutorial/controlflow.html#if-statements — ρss, Dec 29 '15 at 14:18
Worth a read: https://stackoverflow.com/questions/17166074/most-efficient-way-of-making-an-if-elif-elif-else-statement-when-the-else-is-don — ρss, Dec 29 '15 at 14:21
I'm voting to close this question as off-topic because it belongs on [codereview.se] — Reinstate Monica -- notmaynard, Dec 29 '15 at 22:02
@iamnotmaynard Furthermore, [you haven't explained why you think this question is off-topic on Stack Overflow](http://meta.stackoverflow.com/q/313266/1157100). — 200_success, Dec 29 '15 at 22:06

score 3 · Accepted Answer · answered Dec 29 '15 at 14:09

You can use a for loop. range(5) loops 5 times whatever is inside it. The _ is to indicate that you don't want to use the value returned by the iterator (In this case range(5))

for _ in range(5):
    if (value0 == 100):
        send_rckey(rc_exit)
    else:
        send_rckey(rc_program_up)
        value0 = checkPicture(15)

For better understanding about for loop look at the documentation (Note: xrange is only for Python 2, in Python 3 range is equivalent to xrange)

score 0 · Answer 2 · answered Dec 29 '15 at 16:13

I like to keep use-specific constants in a class, like

class Remote:
    GET_CHANNEL = 15
    CHANNEL_UP = "Ch+"
    OK = "ok"
    EXIT = "exit"

    def up_to_channel(self, wanted_channel, max_ups=5):
        for _ in range(max_ups):
            this_channel = checkPicture(Remote.GET_CHANNEL)
            if this_channel == wanted_channel:
                send_rckey(Remote.EXIT)
                return True   # Success
            else:
                send_rckey(Remote.CHANNEL_UP)
        # didn't find it
        return False   # Failure

How can i shorten this python code

2 Answers2