Python 尝试打开/写入文件时语法无效
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Invalid syntax when trying to open/write a file
提问by user2650312
Recently, I installed my new DS18B20 temperature sensor, using the Raspberry Pi. It works well and I managed to modify a program from the Adafruit learning system in order to get temperature when asked through keyboard input. Next step, I am trying to write the temperature readings in a file. The entire code is :
最近，我使用 Raspberry Pi 安装了我的新 DS18B20 温度传感器。它运行良好，我设法修改了 Adafruit 学习系统中的程序，以便在通过键盘输入询问时获取温度。下一步，我试图将温度读数写入文件。整个代码是：
import os
import glob
import time
import sys
os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')
base_dir = '/sys/bus/w1/devices/'
device_folder = glob.glob(base_dir + '28*')[0]
device_file = device_folder + '/w1_slave'
def read_temp_raw():
f = open(device_file, 'r')
lines = f.readlines()
f.close()
return lines
def read_temp():
lines = read_temp_raw()
while lines[0].strip()[-3:] != 'YES':
time.sleep(0.2)
lines = read_temp_raw()
equals_pos = lines[1].find('t=')
if equals_pos != -1:
temp_string = lines[1][equals_pos+2:]
temp_c = int(temp_string) / 1000.0
return temp_c
def write_temp():
localtime=time.asctime(time.localtime(time.time())
f = open("my temp",'w')
f.write(print localtime,read_temp())
f.close()
while True:
yes = set(['yes','y','ye',''])
no = set(['no','n'])
choix = raw_input("Temperature reading?(Y/N)")
if choix in yes : write_temp()
if choix in no : sys.exit()
The part we are interested in is this one :
我们感兴趣的部分是这个：
def write_temp():
localtime=time.asctime(time.localtime(time.time())
f = open("my temp",'w')
f.write(print localtime,read_temp())
f.close()
The Raspberry sends me this :
树莓派给我这个：
"There's an error in your program : Invalid syntax"
“您的程序中存在错误：语法无效”
And then highlights the "f" from the line "f = open("my temp",'w')"
然后突出显示“f = open(“my temp”,'w')”行中的“f”
I tried also with "fo", it doesn't work. Nevertheless, there is no error when i try to put no logic before the code, like this (it's a test code, it is not related with the previous code) :
我也试过用“fo”，它不起作用。尽管如此，当我尝试在代码之前不添加任何逻辑时没有错误，就像这样（这是一个测试代码，它与之前的代码无关）：
f = open("test",'w')
f.write("hello")
Do you have any clues about how to make it work? It may be simple but I am such a newbie in python and programs in general.
你有任何关于如何使它工作的线索吗？这可能很简单，但总的来说，我是 Python 和程序的新手。
回答by jabgibson
This syntax error is being thrown because the code lacks a closing parentheses ")".
抛出此语法错误是因为代码缺少右括号“)”。
Therefore the next line is throwing the interpreter an error because your previous statement is not complete. This happens frequently.
因此，下一行向解释器抛出错误，因为您之前的语句不完整。这种情况经常发生。
def write_temp():
localtime=time.asctime(time.localtime(time.time()) # <----- need one more ")"
f = open("my temp",'w')
f.write(print localtime,read_temp())
f.close()
