Python Error (Traceback & ValueError) Help!

[helpplease]

Anyone here able to help with some python error messages? 

1. Traceback (most recent call last):
2. ValueError: time data '' does not match format '%Y%m%d'

The code seems to run & execute based on the conditions stated below, up till printing 'we are complete. here is total profit:'.

PLEASE HELP!


this is the code I'm using:

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import time from datetime import datetime from time import mktime     def backTest():       stance = 'none'     buyPrice = 0     sellPrice = 0     previousPrice = 0       totalProfit = 0           bigDataFile = open('AAPL.txt','r')     readFile = bigDataFile.read()     lineSplit = readFile.split('\n')       for everyLine in lineSplit:         dividedLine = everyLine.split(',')         initialDate = dividedLine[0]         unixStamp = mktime(datetime.strptime(initialDate, '%Y%m%d').timetuple())         dateStamp = time.strftime('%d/%m/%Y',time.localtime(unixStamp))         stockPrice = float(dividedLine[4])         reformatted = unixStamp,dateStamp,stockPrice           if stance == 'none':             if stockPrice < previousPrice:                 print 'buy triggered!'                 buyPrice = stockPrice                 print 'bought stock for',buyPrice                 stance = 'holding'           elif stance == 'holding':             if stockPrice > buyPrice * .002 + buyPrice:                 print 'sell triggered!'                 sellPrice = stockPrice                 print 'finished trade, sold for:',sellPrice                 stance = 'none'                 tradeProfit = sellPrice - buyPrice                 totalProfit += tradeProfit                 print totalProfit           previousPrice = stockPrice       print 'we are complete. here is total profit:'     print totalProfit     time.sleep(555)   backTest()

[Larz60+]

In the future, please use code tags (I added them this time)

I'm thinking that dividedLine[0] is not a timestamp.
try printing the contents before the conversion

[helpplease]

In the future, please use code tags (I added them this time)

I'm thinking that dividedLine[0] is not a timestamp.
try printing the contents before the conversion

My apologies. I am new to this. Thanks for your help!

It does print & initialDate is a timestamp. Would you be able to explain, in words, what the two error messages actually mean & how I am to interpret them? Maybe, that way, I could troubleshoot it myself?

Thanks!

[Larz60+]

Please post the entire traceback, it contains valuable information
that shows the context of the error.
please show print result

[Ofnuts]

Traceback is followed by "the stack" (ie, the state of nested function calls...). One end of the stack is where your code has crashed (which is why providing the whole traceback when you ask for help is a good idea).

The "ValueError" is an usual answer in Python to an invalid argument in a function call. Given the message it is likely the strptime() call telling you that it cannot parse its input with the format you provided.