Python: SyntaxError: 'return' außerhalb der Funktion

def get_temp():

   temp_c = None

   temp_f = None

   lines = read_data()

   # If the end of the first line ends with something other than

   # 'YES'

   # Try reading the file again until 'YES' is found.

   while not lines[0].strip().endswith('YES'):

      time.sleep(0.25)

      lines = read_data()

      # Search the second line for the data prefixed with 't='

      pos = lines[1].find('t=')

      # A return code of -1 means it wasn't found.

      if pos != -1:

      # Get the raw data located after the 't=' until the end of the

      temp_string = lines[1][ pos+2:]

      # Convert the scale for printing

      temp_c = float(temp_string) / 1000.00

      # Convert to Farenheit

      temp_f = temp_c * 9.00 / 5.00 + 32.00


   return temp_c, temp_f

Einrückung, wenn das hilft

Hier ist eine richtig eingerückte Version Ihres Codes. Sie hatten auch eine Mischung aus Tabulatoren und 4 Leerzeichen, die vermieden werden sollte, da dies häufig Probleme verursacht.

# RasPi Temperature Sensor - Beginning Sensor Networks
#
# For this script, we explore connecting a digital temperature sensor
# to the Raspberry Pi and reading the data. We display the
# temperature
# in Celsius and Fahrenheit.

# Import Python modules (always list in alphabetical order)
import glob
import os
import time

# Issue the modprobe statements to initialize the GPIO and
# temperature sensor modules
os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')

# Use glob to search the file system for directories that match the
# prefix.

# Save the path to the directory.
datadir = glob.glob('/sys/bus/w1/devices/28*')[0]

# Create the full path to the file
datafile = os.path.join(datadir, 'w1_slave')

# Procedure for reading the raw data from the file.
# Open the file and read all of the lines then close it.
def read_data():
    f = open(datafile, 'r')
    lines = f.readlines()
    f.close()
    return lines

# Read the temperature and return the values found.
def get_temp():
    # Initialize the variables.
    temp_c = None
    temp_f = None
    lines = read_data()

    # If the end of the first line ends with something other than
    # 'YES'

    # Try reading the file again until 'YES' is found.
    while not lines[0].strip().endswith('YES'):
        time.sleep(0.25)
        lines = read_data()
        # Search the second line for the data prefixed with 't='
        pos = lines[1].find('t=')

        # A return code of -1 means it wasn't found.
        if pos != -1:
            # Get the raw data located after the 't=' until the end of the
            temp_string = lines[1][ pos+2:]
            # Convert the scale for printing
            temp_c = float(temp_string) / 1000.00
            # Convert to Farenheit
            temp_f = temp_c * 9.00 / 5.00 + 32.00

    return temp_c, temp_f

# Main loop. Read data then sleep 1 second until cancelled with CTRL-
# C.
while True:
    temp_c, temp_f = get_temp()
    print("Temperature is {0} degrees Celsius, "
          "{1} degrees Fahrenheit.".format(temp_c, temp_f))
    time.sleep(1)