我遇到了一个问题，我花了几个小时才解决它。我确信这只是一件小事，但不知何故我不知道我做错了什么。
我的目标是通过 json 从公共(public)交通公司获取数据，并在显示屏上显示地铁/电车的下一个出发时间。基本上一切正常，但一旦 json 返回变音符号(如“ü”)，我就会收到一条错误消息。有趣的是:升号 s (ß) 有效!
这是确切的错误消息(应该是“Hütteldorf”):
UnicodeEncodeError('ascii', u'H\xfctteldorf', 1, 2, 'ordinal not in range(128)')
部分代码:
...
apiurl = 'https://www.wienerlinien.at/ogd_realtime/monitor?rbl={rbl}&sender={apikey}'
...
for rbl in rbls:
r = requests.get(url, timeout=10)
##r.encoding = 'utf-8';
##print(r.json())
##print(r.encoding)
##r.encoding = 'latin1'
if requests.codes.ok:
try:
for monitor in r.json()['data']['monitors']:
rbl.station = monitor['locationStop']['properties']['title'].encode('utf-8')
for line in monitor['lines']:
#Decoding-Problem is here - ß works, ü doesn't
#UnicodeEncodeError('ascii', u'H\xfctteldorf', 1, 2, 'ordinal not in range(128)')
rbl.name = str(line['name'])
rbl.direction = str(line['towards'])
rbl.trafficjam = line['trafficjam'] #Boolean
...
我个人认为我尝试了 Python3 中所有可能的方法...编码、解码...每次升号 s 或元音变音 ü 失败时。
有人能给我正确方向的提示吗？ 非常感谢!
[编辑:] 这是完整的源代码，其中有一个解决方法(ü=ue):
#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys, getopt, time
import requests
import smbus
# Define some device parameters
I2C_ADDR = 0x27 # I2C device address, if any error, change this address to 0x3f
LCD_WIDTH = 20 # Maximum characters per line
# Define some device constants
LCD_CHR = 1 # Mode - Sending data
LCD_CMD = 0 # Mode - Sending command
LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line
LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line
LCD_BACKLIGHT = 0x08 # On
#LCD_BACKLIGHT = 0x00 # Off
ENABLE = 0b00000100 # Enable bit
# Timing constants
E_PULSE = 0.0005
E_DELAY = 0.0005
#Open I2C interface
bus = smbus.SMBus(1) # Rev 2 Pi uses 1
class RBL:
id = 0
line = ''
station = ''
direction = ''
time = -1
def replaceUmlaut(s):
s = s.replace("Ä", "Ae") # A umlaut
s = s.replace("Ö", "Oe") # O umlaut
s = s.replace("Ü", "Ue") # U umlaut
s = s.replace("ä", "ae") # a umlaut
s = s.replace("ö", "oe") # o umlaut
s = s.replace("ü", "ue") # u umlaut
return s
def lcd_init():
# Initialise display
lcd_byte(0x33,LCD_CMD) # 110011 Initialise
lcd_byte(0x32,LCD_CMD) # 110010 Initialise
lcd_byte(0x06,LCD_CMD) # 000110 Cursor move direction
lcd_byte(0x0C,LCD_CMD) # 001100 Display On,Cursor Off, Blink Off
lcd_byte(0x28,LCD_CMD) # 101000 Data length, number of lines, font size
lcd_byte(0x01,LCD_CMD) # 000001 Clear display
time.sleep(E_DELAY)
def lcd_byte(bits, mode):
# Send byte to data pins
# bits = the data
# mode = 1 for data
# 0 for command
bits_high = mode | (bits & 0xF0) | LCD_BACKLIGHT
bits_low = mode | ((bits<<4) & 0xF0) | LCD_BACKLIGHT
# High bits
bus.write_byte(I2C_ADDR, bits_high)
lcd_toggle_enable(bits_high)
# Low bits
bus.write_byte(I2C_ADDR, bits_low)
lcd_toggle_enable(bits_low)
def lcd_toggle_enable(bits):
# Toggle enable
time.sleep(E_DELAY)
bus.write_byte(I2C_ADDR, (bits | ENABLE))
time.sleep(E_PULSE)
bus.write_byte(I2C_ADDR,(bits & ~ENABLE))
time.sleep(E_DELAY)
def lcd_string(message,line):
# Send string to display
message = message.ljust(LCD_WIDTH," ")
lcd_byte(line, LCD_CMD)
for i in range(LCD_WIDTH):
lcd_byte(ord(message[i]),LCD_CHR)
def main(argv):
apikey = False
apiurl = 'https://www.wienerlinien.at/ogd_realtime/monitor?rbl={rbl}&sender={apikey}'
#Time between updates
st = 10
# Initialise display
lcd_init()
lcd_string("Willkommen!",LCD_LINE_2)
try:
opts, args = getopt.getopt(argv, "hk:t:", ["help", "key=", "time="])
except getopt.GetoptError:
usage()
sys.exit(2)
for opt, arg in opts:
if opt in ("-h", "--help"):
usage()
sys.exit()
elif opt in ("-k", "--key"):
apikey = arg
elif opt in ("-t", "--time"):
try:
tmpst = int(arg)
if tmpst > 0:
st = tmpst
except ValueError:
usage()
sys.exit(2)
if apikey == False or len(args) < 1:
usage()
sys.exit()
rbls = []
for rbl in args:
tmprbl = RBL()
tmprbl.id = rbl
rbls.append(tmprbl)
x = 1
while True:
for rbl in rbls:
url = apiurl.replace('{apikey}', apikey).replace('{rbl}', rbl.id)
r = requests.get(url, timeout=10)
r.encoding = 'utf-8'
if requests.codes.ok:
try:
for monitor in r.json()['data']['monitors']:
rbl.station = monitor['locationStop']['properties']['title']
for line in monitor['lines']:
rbl.name = replaceUmlaut(str(line['name'].encode('ascii','xmlcharrefreplace').decode('ascii')))
rbl.direction = replaceUmlaut(str(line['towards'].encode('ascii','xmlcharrefreplace').decode('ascii')))
rbl.trafficjam = line['trafficjam']
rbl.type = line['type']
rbl.time1 = line['departures']['departure'][0]['departureTime']['countdown']
rbl.time2 = line['departures']['departure'][1]['departureTime']['countdown']
rbl.time3 = line['departures']['departure'][2]['departureTime']['countdown']
lcdShow(rbl)
time.sleep(st)
except Exception as e:
print("Fehler (Exc): " + repr(e))
print(r)
lcd_string("Fehler (Exc):",LCD_LINE_1)
lcd_string(repr(e),LCD_LINE_2)
lcd_string("",LCD_LINE_3)
lcd_string("",LCD_LINE_4)
else:
print('Fehler bei Kommunikation mit Server')
lcd_string("Fehler:",LCD_LINE_1)
lcd_string("Serverkomm.",LCD_LINE_2)
lcd_string("",LCD_LINE_3)
lcd_string("",LCD_LINE_4)
def lcdShow(rbl):
lcdLine1 = rbl.name + ' ' + rbl.station
lcdLine2 = rbl.direction
lcdLine3 = "".ljust(LCD_WIDTH-9) + ' ' + '{:0>2d}'.format(rbl.time1) + ' ' + '{:0>2d}'.format(rbl.time2) + ' ' + '{:0>2d}'.format(rbl.time3)
if not rbl.type == "ptMetro":
if rbl.trafficjam:
lcdLine4 = "Stau in Zufahrt"
else:
lcdLine4 = "kein Stau"
else:
lcdLine4 = ""
lcd_string(lcdLine1,LCD_LINE_1)
lcd_string(lcdLine2,LCD_LINE_2)
lcd_string(lcdLine3,LCD_LINE_3)
lcd_string(lcdLine4,LCD_LINE_4)
#print(lcdLine1 + '\n' + lcdLine2+ '\n' + lcdLine3+ '\n' + lcdLine4)
def usage():
print('usage: ' + __file__ + ' [-h] [-t time] -k apikey rbl [rbl ...]\n')
print('arguments:')
print(' -k, --key=\tAPI key')
print(' rbl\t\tRBL number\n')
print('optional arguments:')
print(' -h, --help\tshow this help')
print(' -t, --time=\ttime between station updates in seconds, default 10')
if __name__ == "__main__":
main(sys.argv[1:])
最佳答案
I personally think I tried everything I found that is possible in Python3...encode, decode, ... Every time either the sharp s or the umlaut ü is failing.
正如评论中所述，根据您看到的错误消息，您似乎正在运行 Python 2。
Python 2 有两种“字符串”类型，包含原始字节的 str 和包含 unicode 字符的 unicode 。当您调用 .json() 时，您将返回一个包含 unicode 字符串的数据结构。所以 line['name'] 就是这样一个 unicode 字符串。
当您调用 str(line['name']) 时，您隐式要求将 unicode 字符串编码为< em>ASCII 字节。这会失败，因为 ASCII 无法表示这些字符。不幸的是，我不知道你为什么要在这里这样做。 rbl.name 是否需要是 str ？它用在哪里？使用它的其他代码预计采用什么编码？
在评论中，Jorropo 建议编写 line['name'].decode("utf-8") 您指出这也不起作用。这是因为对 unicode 字符串进行de编码并没有什么意义，但Python 2无论如何都会先尝试en编码在按照您的要求尝试以 UTF-8 进行解码之前，先以 ASCII 格式(失败)。
您的修复将取决于您对 rbl.name 所做的操作。你可能会:
- 直接使用unicode字符串即可。
rbl.name = line['name']这要求后续代码需要一个 unicode 字符串。 - 将其编码为 UTF-8 字节。
rbl.name = line['name'].encode('utf-8')这要求后续代码需要 UTF-8 字节序列。
无论哪种方式，当您尝试其中任何一种方法时，都有可能(甚至可能)其他东西随后会中断，这完全取决于代码的其余部分对 rbl.name 所做的假设应该是什么以及它是如何编码的。
至于为什么它与 u'Westbahnstraße' 配合使用，我无法确定。您能否提供一个完整的示例，包括演示一个工作而另一个不工作的输入数据？
关于python - Python3 中德语元音变音的编码/解码，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59346377/