Subtracting dates to get hours and minutes

[MRAB]

On 2022-12-15 18:14, Gronicus at SGA.Ninja wrote:
> So far so good , I can now use a variable in datetime.datetime but it only
> works if I hard-code the time/date information. Now I want to have the code
> read from a file but I get: TypeError: function takes at most 9 arguments
> (26 given)
> 
> I figure that the structure in the file is incorrect. What should it be? The
> entry in the file is (2022, 12, 13,  5,  3, 30) but when my program tries to
> use it I get the error.
> 
> The program is a bit more sophisticated now but here is the update with a
> sample of the SPECIFICATIONS.txt file:
> =====================================================================
> 
> # This program compares two Timedate values, subtracts the two and
> # converts the difference to seconds and hours.
> #
> 
> #  %A Monday    #  %a Mon           #  %B January   #  %b Jan
> #  %d 05 day    #  %m month as 01   #  %Y 2020      #  %y 20
> #  %H 24        #  %I 12            #  %M 30 min    #  %S Seconds
> 
> import time
> import datetime
> from time import gmtime, strftime ##define strftime as time/date right now
> # ======================================================
> 
> def GetSpecByItem(GetThisOne):  #get line by item in column 4 - 7
>      ItemValue = "--"
>      
>      with open("SPECIFICATIONS.txt" , 'r') as infile:
>       for lineEQN in infile: # loop to find each line in the file for that
> dose
>          if ((lineEQN[4:7]== GetThisOne)):

You don't need the parentheses, and certainly 2 pairs of them!

>             ItemValue = lineEQN[30:60].strip()   # Just the Data
>      return(ItemValue)

You're returning a _string_.

I suggest using 'literal_eval' from the 'ast' module to convert the 
string safely into a tuple.

However, if the 'for' loop fails to match a line, the function will 
return "--", which won't be of any use later on unless you check for it 
specifically and, say, report an error to the user.

> 
> """
> SPECIFICATIONS.txt
> 
> IYf HRB Humalog R Date           (2018, 12, 4, 10,  7, 00)           ##
> IYf HRG Humulin R Date           (2022, 12, 13,  5,  3, 30)          ##
> """
> # ====================== Main() ======================================
> print()
> Startt = "404"
> Stopp  = "404"
> 
> Answer = "Y"
> Answer = input("Run test A? (" + Answer + ")" )
> 
> if Answer == "Y" or Answer == "y" or Answer == "":
>     print()
>     print("     Running Test A:")
> #           Year  Mth Day Hour Min Sec
>     Startt  =   2018, 12, 4, 10,  7, 00
>     Stopp   =   2022, 12, 12, 1, 15, 30
>     NowTime =   2022, 12, 14, 21, 15, 30

'Startt' and 'Stopp' here are tuples.

> else:
>     print("     Running Test B:")
>     Startt = GetSpecByItem("HRG")
>     Stopp =  GetSpecByItem("HRB")

'Startt' and 'Stopp' here are _strings_.

>     NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")
>     
> print()
> print("55    NowTime = " + str(NowTime))
> print("56     Startt = " + str(Startt))
> print("57      Stopp = " + str(Stopp))
> print()
> 
> NowTime =  datetime.datetime(*NowTime)
> Startt =   datetime.datetime(*Startt)
> Stopp =    datetime.datetime(*Stopp)
> 
These will work if 'Startt' and 'Stopp' are tuples, but not if they're 
strings. In the latter case, you're effectively passing multiple 
single-characters strings into 'datetime'.

> #Start == Startt  # True"
> #print("Startt test = " + Start)
> # =================================================
> print()
> c = NowTime - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print ("77 Hours =     <" + str(hours) + ">")
> print ("78 Minutes =   <" + str(minutes) + ">")
> if hours > 7:
>      print(" Time to inject Humulin R u500.")
> 
> pause = input("Pause")
> # ======================================================
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
> Behalf Of Thomas Passin
> Sent: Tuesday, December 13, 2022 11:20 PM
> To: python-list at python.org
> Subject: Re: Subtracting dates to get hours and minutes
> 
> Your problem is that datetime.datetime does not accept a tuple as an
> argument.  It expects an integer value for the first argument, but you
> supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
> list) the way you want by prefixing it with an asterisk.  This causes the
> sequence of items to be treated as individual arguments. So:
> 
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
> st1 = (2022, 12, 13,  5,  3, 30)
> dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
> dts1 == Startt  # True
> 
> On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>>   As is, Test A works.
>>   Comment out Test A and uncomment Test B it fails.
>>   In Test B, I move the data into a variable resulting with the report:
>>              "TypeError: an integer is required (got type tuple)
>> 
>> How do I fix this?
>> 
>> #---------------------------------------------------------------------
>> --------
>> import datetime
>> #=================================================
>> #         Test A   Hard coded Date/Time
>> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =  
>> datetime.datetime(2022, 12, 12, 21, 15, 30)
>> 
>> # =================================================
>> #         Test B   Date/Time data as a variable
>> #Startt = (2022, 12, 13,  5,  3, 30)
>> #Stopp =  (2022, 12, 12, 21, 15, 30)
>> 
>> #Startt = datetime.datetime(Startt)
>> #Stopp =  datetime.datetime(Stopp)
>> 
>> # =================================================
>> c = Startt - Stopp
>> minutes = c.total_seconds() / 60
>> minutes = c.seconds / 60
>> hours = 0
>> 
>> while (minutes > 59):
>>          minutes = minutes - 60
>>          hours += 1
>> minutes = round(minutes)
>> print()
>> print ("       Hours =  <" + str(hours) + ">")
>> print ("     Minutes =  <" + str(minutes) + ">")
>> 
>> # 
>> ----------------------------------------------------------------------
>> -------
>> 
> 
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