python - PinoroEnviro+ 类型错误 : argument should be integer or bytes-like object, 而不是 'str'

Question

我一直在尝试理解当我运行我购买的某些硬件附带的示例时报告的错误。

我尝试过谷歌搜索，但得到的每个答案都有点超出我的理解范围。我认为问题在于该脚本或导入的脚本之一是为 Python 2 编写的，而我正在尝试在 python 3 中运行它。当我尝试在 Python 2 中运行它时，我遇到了很多其他问题，因此我一直在尝试让它在 Python 3 中运行。

我购买的硬件是 Pimoroni 销售的树莓派的 Enviro+ 传感器套件

Hardware Link

Github Library

Pimoroni Tutorial

#!/usr/bin/env python

import time
import colorsys
import os
import sys
import ST7735
import ltr559

from bme280 import BME280
from pms5003 import PMS5003
from enviroplus import gas
from subprocess import PIPE, Popen
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont

print("""all-in-one.py - Displays readings from all of Enviro plus' sensors

Press Ctrl+C to exit!

""")

# BME280 temperature/pressure/humidity sensor
bme280 = BME280()

# PMS5003 particulate sensor
pms5003 = PMS5003()

# Create ST7735 LCD display class
st7735 = ST7735.ST7735(
    port=0,
    cs=1,
    dc=9,
    backlight=12,
    rotation=270,
    spi_speed_hz=10000000
)

# Initialize display
st7735.begin()

WIDTH = st7735.width
HEIGHT = st7735.height

# Set up canvas and font
img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
draw = ImageDraw.Draw(img)
path = os.path.dirname(os.path.realpath(__file__))
font = ImageFont.truetype(path + "/fonts/Asap/Asap-Bold.ttf", 20)

message = ""

# The position of the top bar
top_pos = 25


# Displays data and text on the 0.96" LCD
def display_text(variable, data, unit):
    # Maintain length of list
    values[variable] = values[variable][1:] + [data]
    # Scale the values for the variable between 0 and 1
    colours = [(v - min(values[variable]) + 1) / (max(values[variable])
               - min(values[variable]) + 1) for v in values[variable]]
    # Format the variable name and value
    message = "{}: {:.1f} {}".format(variable[:4], data, unit)
    print(message)
    draw.rectangle((0, 0, WIDTH, HEIGHT), (255, 255, 255))
    for i in range(len(colours)):
        # Convert the values to colours from red to blue
        colour = (1.0 - colours[i]) * 0.6
        r, g, b = [int(x * 255.0) for x in colorsys.hsv_to_rgb(colour,
                   1.0, 1.0)]
        # Draw a 1-pixel wide rectangle of colour
        draw.rectangle((i, top_pos, i+1, HEIGHT), (r, g, b))
        # Draw a line graph in black
        line_y = HEIGHT - (top_pos + (colours[i] * (HEIGHT - top_pos)))\
                 + top_pos
        draw.rectangle((i, line_y, i+1, line_y+1), (0, 0, 0))
    # Write the text at the top in black
    draw.text((0, 0), message, font=font, fill=(0, 0, 0))
    st7735.display(img)


# Get the temperature of the CPU for compensation
def get_cpu_temperature():
    process = Popen(['vcgencmd', 'measure_temp'], stdout=PIPE)
    output, _error = process.communicate()
    return float(output[output.index('=') + 1:output.rindex("'")])


# Tuning factor for compensation. Decrease this number to adjust the
# temperature down, and increase to adjust up
factor = 0.8

cpu_temps = [0] * 5

delay = 0.5  # Debounce the proximity tap
mode = 0  # The starting mode
last_page = 0
light = 1

# Create a values dict to store the data
variables = ["temperature",
             "pressure",
             "humidity",
             "light",
             "oxidised",
             "reduced",
             "nh3",
             "pm1",
             "pm25",
             "pm10"]

values = {}

for v in variables:
    values[v] = [1] * WIDTH

# The main loop
try:
    while True:
        proximity = ltr559.get_proximity()

        # If the proximity crosses the threshold, toggle the mode
        if proximity > 1500 and time.time() - last_page > delay:
            mode += 1
            mode %= len(variables)
            last_page = time.time()

        # One mode for each variable
        if mode == 0:
            variable = "temperature"
            unit = "C"
            cpu_temp = get_cpu_temperature()
            # Smooth out with some averaging to decrease jitter
            cpu_temps = cpu_temps[1:] + [cpu_temp]
            avg_cpu_temp = sum(cpu_temps) / float(len(cpu_temps))
            raw_temp = bme280.get_temperature()
            data = raw_temp - ((avg_cpu_temp - raw_temp) / factor)
            display_text(variable, data, unit)

        if mode == 1:
            variable = "pressure"
            unit = "hPa"
            data = bme280.get_pressure()
            display_text(variable, data, unit)

        if mode == 2:
            variable = "humidity"
            unit = "%"
            data = bme280.get_humidity()
            display_text(variable, data, unit)

        if mode == 3:
            variable = "light"
            unit = "Lux"
            if proximity < 10:
                data = ltr559.get_lux()
            else:
                data = 1
            display_text(variable, data, unit)

        if mode == 4:
            variable = "oxidised"
            unit = "kO"
            data = gas.read_all()
            data = data.oxidising / 1000
            display_text(variable, data, unit)

        if mode == 5:
            variable = "reduced"
            unit = "kO"
            data = gas.read_all()
            data = data.reducing / 1000
            display_text(variable, data, unit)

        if mode == 6:
            variable = "nh3"
            unit = "kO"
            data = gas.read_all()
            data = data.nh3 / 1000
            display_text(variable, data, unit)

        if mode == 7:
            variable = "pm1"
            unit = "ug/m3"
            data = pms5003.read()
            data = data.pm_ug_per_m3(1.0)
            display_text(variable, data, unit)

        if mode == 8:
            variable = "pm25"
            unit = "ug/m3"
            data = pms5003.read()
            data = data.pm_ug_per_m3(2.5)
            display_text(variable, data, unit)

        if mode == 9:
            variable = "pm10"
            unit = "ug/m3"
            data = pms5003.read()
            data = data.pm_ug_per_m3(10)
            display_text(variable, data, unit)

# Exit cleanly
except KeyboardInterrupt:
    sys.exit(0)

当我尝试运行代码时，我得到以下结果:

Traceback (most recent call last):
  File "all-in-one.py", line 135, in <module>
    cpu_temp = get_cpu_temperature()
  File "all-in-one.py", line 89, in get_cpu_temperature
    return float(output[output.index('=') + 1:output.rindex("'")])
TypeError: argument should be integer or bytes-like object, not 'str'

如果我没有正确填写此帮助请求，请原谅我 - 我对论坛非常陌生(我几乎从来没有在论坛上发过帖子，尽管我阅读了很多论坛来寻求帮助)，而且我对 Python 也很陌生， Linux。

我们将非常感谢社区的任何帮助和支持 - 预先感谢您...

软件

Answer 1

根据Python 3 whitepages on subprocess.communicate() ，output 和 _error 的类型可以是字符串(您想要的)OR 字节。如果您要返回字符串，则不会遇到此问题，但您收到的 TypeError 消息正是您尝试调用 index() 时收到的消息在带有字符串参数的 bytes 对象上。

明显:

>>> output = "temperature = '88 C'".encode('utf-8') #this is of type bytes
>>> output
b"temperature = '88 C'"
>>> output.index('=')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: argument should be integer or bytes-like object, not 'str'
>>> output.index(ord('='))
12

因此，您应该将 output.index('=') 替换为 output.index(ord('=')) 和 output.rindex("'") 与 output.rindex(ord("'"))。

编辑

我很晚才意识到这一点，但您可以通过在搜索字符串前面添加 b 来规避使用 ord()。

output.index(b'=')