python codes

[Michael Manubay]

Can someone help me please to understand this lines if ever someone has knowledge to these. I dont know what is the meaning of "Places" and the number 2 inside the parentheses.

#Read Temperature sensor
def ReadTemperature(places):
    humidity, temperature = Adafruit_DHT.read_retry(sensor,pin)
    temperature = round(humidity,places)
    return temperature


while True:
#take Temperature Reading via DHT22
    temperature_percentage = ReadTemperature(2)

[Monica Shiralkar]

That is a variable that you have created and passing to the function.

[Tim Holloway]

I'm guessing that you're using Circuit Python. I moved this question to the Arduino forum, although it's possible that you're using a Raspberry Pi. I just happen to use the DHT units on Arduinos - although in Arduino's C++ like language, not Python.

The round() function takes a numeric value (humidity) and rounds it to a specified number of decimal places. And actually, that code is defective, because it's treating temperature and humidity as the same thing. In this case, since you passed the value 2 to ReadTemperature, it rounds the humidity (!!!) to 2 decimals, then returns it as a "temperature".

The proper code should be like this:

#Read Temperature sensor
def ReadTemperature(places):
    humidity, temperature = Adafruit_DHT.read_retry(sensor,pin)
    rnd_temperature = round(temperature,places)
    return rnd_temperature


while True:
#take Temperature Reading via DHT22
    temperature_percentage = ReadTemperature(2)

I don't know what generally-accepted name formation rules are for Python, but I always use either C-like (read_temperature) or Java-like (readTemperature). Beginning a name with a capital letter is usually something only done for classnames and constant names (which are generally all upper-case).

And the code tags goe around the formatted text. That's why my code is in a box, but yours has an empty box and no pretty code. Check Use Code Tags for details.

[Ron McLeod]

Michael Manubay wrote:I dont know what is the meaning of "Places" ...

Places specifies the number of devcimal places to use with the Python round function

Michael Manubay wrote:... and the number 2 inside the parentheses.

It most likely means than there are multiple DHT sensors, and the number 2 specifies to read from the the senor on GPIO pin #2.


Edit: looks like I didn't read the question properly and I didn't notice Tim's response. Ugh