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Orizzon
Asked: 2020-08-28 17:40:13 +0800 CST 2020-08-28 17:40:13 +0800 CST

Doubt about write method

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A very simple question, if writeI want to write two things, how should I do it?

An example:

import serial
ser = serial.Serial('/dev/ttyACM0', 9600)
while True:
    entrada = input("Introduce el angulo: ")
    ser.write(str(entrada))

What do I have to do here so that he writewrites la entradaand then a 1 after it and that, if I entradawrite 90 , he writesends 901 ?

python

1 Answers

  1. Best Answer

    You just have to concatenate both strings:

    ser.write((str(entrada) + "1").encode())

    Or using str.format():

    ser.write("{}1".format(entrada).encode())

    In Python >= 3.6 you can use formatted string literals:

    ser.write(f"{entrada}1".encode())

    It is important to ensure that writebytes are passed to it and not an encoded string or other data type (hence the use of encode). In Python 2, if we are sure that the result is of type, strit is not necessary. This code is valid for Python 2 and Python 3.

    On the other hand, using inputPython 2 for unfiltered user input is very dangerous since it executes all valid code entered. Instead you should use raw_inputwhich, as inputin Python 3, returns an object str. See Doubt with raw_input() for more information.

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