How to write an integer variable to log file with f.write? - python

This script is a simple while True loop that checks a voltage value and writes a log file. However, I am not able to get the voltage value written in the log.
Simple log files with a text string and date / timestamp work fine but the write fails when I try to use the variable name.
ina3221 = SDL_Pi_INA3221.SDL_Pi_INA3221(addr=0x40)
LIPO_BATTERY_CHANNEL = 1
busvoltage1 = ina3221.getBusVoltage_V(LIPO_BATTERY_CHANNEL)
while True:
if busvoltage1 <= 3.70:
with open("/<path>/voltagecheck.log", "a") as f:
f.write("battery voltage below threshold: " + busvoltage1 + "\n")
f.write("timestamp: " + time.asctime() + "\n")
f.write("-------------------------------------------" + "\n")
f.close()
else:
time.sleep(3600)
I've also tried:
with open("/<path>/voltagecheck.log", "a") as f:
f.write("battery voltage below threshold: " + str(busvoltage1) + "\n")
f.write("timestamp: " + time.asctime() + "\n")
f.write("-------------------------------------------" + "\n")
f.close()
Without trying to add the busvoltage1 value to the log, the log is created and the timestamp line works fine.
With the busvoltage1 value, the log is created but nothing is written.
When running this in the terminal, the errors for "str(busvoltage1)" and just the plain "busvoltage1" are:
ValueError: I/O operation on closed file
and
TypeError: cannot concatenate 'str' and 'float' objects

The value needs to be formatted as a string before f.write is used.
Added v = str(busvoltage1) and then referenced v in f.write: f.write(battery voltage below threshold: " + v + "\n")
This is referenced in the 5th example of 7.2.1 here: https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files. Thanks #PatrickArtner

Related

Test Run Failed: local variable '' referenced before assignment

Long time reader, first time poster!
I've been working on setting up the first piece of automation at my workplace and teaching myself my first programming language at the same time. The end goal is to set up a Sikuli script to run testing overnight.
I keep running into errors that feel like a lack of understanding on basic python principles and I don't have anyone around to teach me.
The function do_math parses a .csv file, does some math, and returns those variables in a tuple. I then assign those results into a variable and try to compare them but I keep running into:
Test Run Failed: local variable 'D2LAverage' referenced before assignment
I've tried assigning D2LAverage in a number of different places, making it global, returning a list vs tuples, but it just keeps getting stuck.
<handler.py>
def do_math():
with open ('C:/Program Files/TrueVision Surgical/DSM/Logs/Latency_' + timestr + '.csv', 'r') as csv_file:
csv_reader = csv.reader(csv_file, delimiter=',')
line_count = 0
D2L = []
L2D = []
next(csv_file)
for row in csv_reader:
next
D2L.append(float(row[1]))
L2D.append(float(row[2]))
line_count += 1
else:
D2LAverage = 0
L2DAverage = 0
D2LAverage = float(sum(D2L) / len(D2L))
L2DAverage = float(sum(L2D) / len(L2D))
D2Lvar = sum(pow(x-D2LAverage,2) for x in D2L) / len(D2L) # Get varience
D2Lstd = math.sqrt(D2Lvar) # Calculate STD
L2Dvar = sum(pow(x-L2DAverage,2) for x in L2D) / len(L2D) # Get varience
L2Dstd = math.sqrt(L2Dvar) # Calculate STD
return D2LAverage, D2Lstd, L2DAverage, L2Dstd
<start_script.py> - Calling the above do_math
do_math()
results = do_math()
# Specify the path
path = 'C:/Users/AeosFactory/Desktop/'
# Specify the file name
file_name = "Latency_Results" + "_" + str(datetime.datetime.now().strftime('%Y-%m-%d_%H_%M_%S')) + ".txt"
# Create a file at specified location and do comparison
with open (os.path.join(path, file_name), 'a+') as Latency_Results:
if results[0] <= 85:
Latency_Results.write("Pass" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, D2L Average:" + " " + str(round(D2LAverage,2)) + '\n')
else:
Latency_Results.write("Fail" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, D2L Average:" + " " + str(round(D2LAverage,2)) + '\n')
if D2Lstd <= 10:
Latency_Results.write("Pass" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, D2L Standard Deviation:" + " " + str(round(D2Lstd,2)) + '\n')
else:
Latency_Results.write("Fail" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, D2L Standard Deviation:" + " " + str(round(D2Lstd,2)) + '\n')
if L2DAverage <= 85:
Latency_Results.write("Pass" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, L2D Average:" + " " + str(round(L2DAverage,2)) + '\n')
else:
Latency_Results.write("Fail" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, L2D Average:" + " " + str(round(L2DAverage,2)) + '\n')
if L2Dstd <= 10:
Latency_Results.write("Pass" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, L2D Standard Deviation:" + " " + str(round(L2Dstd,2)) + '\n' + '\n')
else:
Latency_Results.write("Fail" + " - " + "4 Screens, Image Mode 1, Surgery, Live, HC, L2D Standard Deviation:" + " " + str(round(L2Dstd,2)) + '\n' + '\n')
With the exception of global variables, variables aren't shared between python files. If you look in start_script.py you never define D2LAverage anywhere. When you attempt to use it during your if statements you raise an error because Python "doesn't know what you're talking about". I think what caught you up is thinking that the name of the values returned is exposed in the scope of where the function was called. All that gets returned is the return value itself.
At the end of do_math() you have the line return D2LAverage, D2Lstd, L2DAverage, L2Dstd, because Python only allows 1 return value per function these get packaged into a tuple.
In start_script.py you call do_math() twice,
once without capturing the return value
once where you assign the return value to results
If you only care about the results of the function, you'll probably want to remove the first call to it.
To access the individual values returned by do_math() you can either access the desired value directly by indexing into the tuple with results[0], or use tuple unpacking to assign the 4 return values to individual variables, with something like D2LAverage, D2Lstd, L2DAverage, L2Dstd = results.

Python Use Dictionary List? What Do I Use

I am making a type of quiz, and want to know how to compare the results to a text file. After answering the questions with prompted input, the function will return a four digit code. I want that four digit code to be compared to "truecode" in a text file I've written out with additional information like this:
villagername,personality,birthday,zodiac,truecode,species
Ankha,snooty,September 22nd,Virgo,A420,Cat
Bangle,peppy,August 27th,Virgo,A330,Tiger
Bianca,peppy,December 13th,Sagittarius,A320,Tiger
Bob,lazy,January 1st,Capricorn,A210,Cat
Bud,jock,August 8th,Leo,A310,Lion
I want this other information to be printed out.
print("Your villager is " + villagername)
print("They are a " + personality + " type villagers and of the " + species + " species.")
print("Their birthday is " + birthday + " and they are a " + zodiac)
print("I hope you enjoyed this quiz!")
I cannot figure out how to extract this information and compare it to what I have. Should I use a list or a dictionary? I'm getting frustrated trying to Google my question and wondering if I went around it all wrong.
How do I compare the four digit code (that will be returned from another function) to "true code" and get everything spit out like above?
import csv
def compare_codes(true_code):
with open(''file.txt) as csvfile:
details_dict = csv.reader(csvfile)
for i in details_dict:
if i['truecode'] == tru_code:
print("Your villager is:",i['villagername'])
print("They are a " + i['personality'] + " type villagers and of the " + i['species'] + " species.")
print("Their birthday is " + i['birthday'] + " and they are a " + i['zodiac'])
print("I hope you enjoyed this quiz!")
break
compare_codes('A420')
Above code reads the text file and compares the input with truecode value in your file and displays the info.
import csv
def get_data(filename):
with open(filename) as f:
reader = csv.DictReader(f, delimiter=',')
data = {row['truecode']: row for row in reader}
return data
def main():
filename = 'results.txt'
data = get_data(filename)
code = input('Enter code: ')
try:
info = data[code]
print("Your villager is " + info['villagername'])
print("They are a " + info['personality'] +
" type villagers and of the " + info['species'] + " species.")
print("Their birthday is " +
info['birthday'] + " and they are a " + info['zodiac'])
print("I hope you enjoyed this quiz!")
except KeyError:
print('Invalid code')
if __name__ == "__main__":
main()
The type of file that you have is actually called a CSV file. If you wanted to, you could open your text file with any spreadsheet program, and your data would show up in the appropriate cells. Use the csv module to read your data.
import csv
def get_quiz_results(truecode):
with open('your-text-file.txt') as csvfile:
csvreader = csv.reader(csvfile)
for row in csvreader:
# row is a dictionary of all of the items in that row of your text file.
if row['truecode'] == truecode:
return row
And then to print out the info from your text file
truecode = 'A330'
info = get_quiz_results(truecode)
print("Your villager is " + info["villagername"])
print("They are a " + info["personality"] + " type villagers and of the " + info["species"] + " species.")
print("Their birthday is " + info["birthday"] + " and they are a " + info["zodiac"])
print("I hope you enjoyed this quiz!")
When looping over the file, the csv module will turn each line of the file into a dictionary using the commas as separators. The first line is special, and is used to create the dictionary keys.

python wont write even when I use f.close

I'm trying to write some code that outputs some text to a list. output is a variable that is a string which is the name of the file to be written. However whenever I look at the file nothing is written.
with open(output, 'w') as f:
f.write("Negative numbers mean the empty space was moved to the left and positive numbers means it was moved to the right" + '\n')
if A == True:
the_h = node.h
elif A== False:
the_h = 0
f.write("Start " + str(node.cargo) + " " + str(node.f) +" " +str(the_h)+" " + '\n')
if flag == 0:
flag = len(final_solution)
for i in range (1,flag):
node = final_solution[i]
f.write(str(node.e_point - node.parent.e_point) + str(node.cargo) + " " + str(node.f) +'\n')
f.close()
Program looks ok, check if the output is set ok, I set as a dummy filename, it worked, presuming code within the block after open has no compiler/interpreter error. The output file should be in the same directory where the source is.
output = "aa.txt"
with open(output, 'w') as f:
f.write("Negative numbers mean the empty space was moved to the left and positive numbers means it was moved to the right" + '\n')
if A == True:
the_h = node.h
elif A== False:
the_h = 0
f.write("Start " + str(node.cargo) + " " + str(node.f) +" " +str(the_h)+" " + '\n')
if flag == 0:
flag = len(final_solution)
for i in range (1,flag):
node = final_solution[i]
f.write(str(node.e_point - node.parent.e_point) + str(node.cargo) + " " + str(node.f) +'\n')
f.close()
You should not add f.close(), as the with statement will do it for you. Also ensure you don't reopen the file elsewhere with open(output, 'w') as that will erase the file.

Appending to Created File in Python

I have a file, which I am writing data to, however I would like the naming convention to have the time, the file was created at and then stream to the same file for one hour before creating a new text file.
My problem is that I am using a while loop to create the text file while reading from a GPIO and so when the code runs, it creates a new text file every time it moves through the loop. How can I create the file, then write to the existing file for a predetermined amount of time?
import spidev
import time
import datetime
import os
spi = spidev.SpiDev()
spi.open(0,0) #open port 0 of the SPI
count = 0
def timeStamp(fname, fmt ='%Y-%m-%d-%H-%M-%S_{fname}'):
#this function adds the time and date
return datetime.datetime.now().strftime(fmt).format(fname = fname)
def alarm_check(int):
#this function checks the value read in by the SPI
#creating an alarm if the value is 0
if int == 0:
return ("System Alarm!")
else:
return ("System OK")
def write_to_file(int):
# this function will write the current value to a file,
# the time it was read in
# and if the system was im alarm
with open (('SPI_Input_Values'), 'a') as output:
output.write("Input = " + str(int) + '\t' + timeStamp('ADC') + '\t\t' + str(alarm_check(int)) + '\n')
def readadc(adcnum):
#this function will open the SPI and read it to see the current value
# this will then be written to a text value
# using the write_to_file function
if adcnum > 7 or adcnum < 0:
return -1
r = spi.xfer2([1,8 + adcnum << 4,0])
adcout = ((r[1] & 3) << 8) + r[2]
return adcout
while True:
Inp1 = int(round(readadc(0)/10.24)) # defines Inp1 as an integer to be read in
write_to_file(Inp1)
count = count +1
time.sleep(0.1) # puts the systemm to sleep for 0.1 seconds
You need to dynamically create your filename. At the moment it was a hardcoded string. Here's an example:
fname = 'SPI_Input_Values'
fmt ='%Y-%m-%d-%H'
date_str = datetime.datetime.now().strftime(fmt)
file_name = date_str + "_" + fname
with open ((file_name, 'a') as output:
output.write("Input = " + str(int) + '\t' + timeStamp('ADC') + '\t\t' + str(alarm_check(int)) + '\n')
This will constantly append to the file that represents the current hour. When the next hour begins, it will automatically create a new file and begin appending data to it instead.
Something like:
def write_to_file(output, int):
output.write("Input = " + str(int) + '\t' + timeStamp('ADC') + '\t\t' + str(alarm_check(int)) + '\n')
with open (('SPI_Input_Values'), 'a') as output:
while True:
Inp1 = int(round(readadc(0)/10.24)) # defines Inp1 as an integer to be read in
write_to_file(output, Inp1)
count = count +1
time.sleep(0.1)

Python: File Writing Adding Unintentional Newlines on Linux Only

I am using Python 2.7.9. I'm working on a program that is supposed to produce the following output in a .csv file per loop:
URL,number
Here's the main loop of the code I'm using:
csvlist = open(listfile,'w')
f = open(list, "r")
def hasQuality(item):
for quality in qualities:
if quality in item:
return True
return False
for line in f:
line = line.split('\n')
line = line[0]
# print line
itemname = urllib.unquote(line).decode('utf8')
# print itemhash
if hasQuality(itemname):
try:
looptime = time.time()
url = baseUrl + line
results = json.loads(urlopen(url).read())
# status = results.status_code
content = results
if 'median_price' in content:
medianstr = str(content['median_price']).replace('$','')
medianstr = medianstr.replace('.','')
median = float(medianstr)
volume = content['volume']
print url+'\n'+itemname
print 'Median: $'+medianstr
print 'Volume: '+str(volume)
if (median > minprice) and (volume > minvol):
csvlist.write(line + ',' + medianstr + '\n')
print '+ADDED TO LIST'
else:
print 'No median price given for '+itemname+'.\nGiving up on item.'
print "Finished loop in " + str(round(time.time() - looptime,3)) + " seconds."
except ValueError:
print "we blacklisted fool?? cause we skippin beats"
else:
print itemname+'is a commodity.\nGiving up on item.'
csvlist.close()
f.close()
print "Finished script in " + str(round(time.time() - runtime, 3)) + " seconds."
It should be generating a list that looks like this:
AWP%20%7C%20Asiimov%20%28Field-Tested%29,3911
M4A1-S%20%7C%20Hyper%20Beast%20%28Field-Tested%29,4202
But it's actually generating a list that looks like this:
AWP%20%7C%20Asiimov%20%28Field-Tested%29
,3911
M4A1-S%20%7C%20Hyper%20Beast%20%28Field-Tested%29
,4202
Whenever it is ran on a Windows machine, I have no issue. Whenever I run it on my EC2 instance, however, it adds that extra newline. Any ideas why? Running commands on the file like
awk 'NR%2{printf $0" ";next;}1' output.csv
do not do anything. I have transferred it to my Windows machine and it still reads the same. However, when I paste the output into Steam's chat client it concatenates it in the way that I want.
Thanks in advance!
This is where the problem occurs
code:
csvlist.write(line + ',' + medianstr + '\n')
This can be cleared is you strip the space
modified code:
csvlist.write(line.strip() + ',' + medianstr + '\n')
Problem:
The problem is due to the fact you are reading raw lines from the input file
Raw_lines contain \n to indicate there is a new line for every line which is not the last and for the last line it just ends with the given character .
for more details:
Just type print(repr(line)) before writing and see the output

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