gqlQuerry comparing datetime objects - python-2.7

Here is the relevant code copied from my application on GAE.
today = datetime.datetime.strptime(date_variable, "%d/%m/%Y")
yesterday = ref_today - datetime.timedelta(days=1)
tomorrow = ref_today + datetime.timedelta(days=1)
logging.info('%s : %s : %s', yesterday, today, tomorrow)
#2016-02-19 00:00:00 : 2016-02-20 00:00:00 : 2016-02-21 00:00:00
records = db.GqlQuery("SELECT * FROM ProgrammeQueue"
" WHERE scheduledFrom < :1 AND scheduledFrom > :2 "
" ORDER BY scheduledFrom DESC",
tomorrow, yesterday)
Problem Statement :
Output: all records of 19/02/2016 and 20/02/2016
Expected: records = all records of 20/02/2016
What am I doing wrong ?

You query states:
WHERE scheduledFrom < :tomorrow AND scheduledFrom > :yesterday
where tomorrow and yesterday are datetimes. the time is set to 00:00:00, so the results will include dates of 19/02/2016 where the time is greater than
00:00:00.
maybe your query should be rewritten to use date objects not datetime objects (depending on your model definition). or maybe you need to rewrite it to something like this:
records = db.GqlQuery("SELECT * FROM ProgrammeQueue"
" WHERE scheduledFrom < :1 AND scheduledFrom >= :2 "
" ORDER BY scheduledFrom DESC",
tomorrow, today)

Related

PowerBI Create List of Month Dates

Hi in powerbi I am trying to create a list of dates starting from a column in my table [COD], and then ending on a set date. Right now this is just looping through 60 months from the column start date [COD]. Can i specify an ending variable for it loop until?
List.Transform({0..60}, (x) =>
Date.AddMonths(
(Date.StartOfMonth([COD])), x))
Assuming
start=Date.StartOfMonth([COD]),
end = #date(2020,4,30),
One way is to add column, custom column with formula
= { Number.From(start) .. Number.From(end) }
then expand and convert to date format
or you could generate a list with List.Dates instead, and expand that
= List.Dates(start, Number.From(end) - Number.From(start)+1, #duration(1, 0, 0, 0))
Assuming you want start of month dates through June 2023. In the example below, I have 2023 and 6 hard coded, but this could easily come from a parameter Date.Year(DateParameter) or or column Date.Month([EndDate]).
Get the count of months with this:
12 * (2023 - Date.Year([COD]) )
+ (6 - Date.Month([COD]) )
+ 1
Then just use this column in your formula:
List.Transform({0..[Month count]-1}, (x) =>
Date.AddMonths(Date.StartOfMonth([COD]), x)
)
You could also combine it all into one harder to read formula:
List.Transform(
{0..
(12 * ( Date.Year(DateParameter) - Date.Year([COD]) )
+ ( Date.Month(DateParameter) - Date.Month([COD]) )
)
}, (x) => Date.AddMonths(Date.StartOfMonth([COD]), x)
)
If there is a chance that COD could be after the End Date, you would want to include error checking the the Month count formula.
Generate list:
let
Start = Date1
, End = Date2
, Mos = ElapsedMonths(End, Start) + 1
, Dates = List.Transform(List.Numbers(0,Mos), each Date.AddMonths(Start, _))
in
Dates
ElapsedMonths(D1, D2) function def:
(D1 as date, D2 as date) =>
let
DStart = if D1 < D2 then D1 else D2
, DEnd = if D1 < D2 then D2 else D1
, Elapsed = (12*(Date.Year(DEnd)-Date.Year(DStart))+(Date.Month(DEnd)-Date.Month(DStart)))
in
Elapsed
Of course, you can create a function rather than hard code startdate and enddate:
(StartDate as date, optional EndDate as date, optional Months as number)=>
let
Mos = if EndDate = null
then (if Months = null
then error Error.Record("Missing Parameter", "Specify either [EndDate] or [Months]", "Both are null")
else Months
)
else ElapsedMonths(StartDate, EndDate) + 1
, Dates = List.Transform(List.Numbers(0, Mos), each Date.AddMonths(StartDate, _))
in
Dates

Conversion to UTC timezone in C++ leaves the time intact (regardless of the original timezone)

I am working with a dataset that contains the following information: date and time in the form "yyyy-mm-dd", "hh:mm". It also contains the name of the US state where the time has been measured. My goal is to unify all the time measurements so that they are all in the UTC timezone. I have written a code that doesn't work and I don't intend to go through the details of that code. However, in order to check why my code doesn't work, I have written a simple test that also doesn't work. The test is as follows:
I have tried to convert "Friday January 1 2021 9:00 AM California" to its equivalent UTC time which is "Friday January 1 2021 5:00 PM". The code snippet for conversion comes in the following:
struct tm calTM;
calTM.tm_hour = 9;
calTM.tm_min = 0;
calTM.tm_year = 2021-1900;
calTM.tm_mon = 1-1;
calTM.tm_mday = 1;
calTM.tm_isdst = -1;
setenv("TZ", "America/California", 1);
time_t calTime = mktime(&calTM);
unsetenv("TZ");
struct tm* utcTime;
utcTime = gmtime(&calTime);
cout << "UTC hh: " << utcTime->tm_hour << ", UTC mm: " << utcTime->tm_min;
cout << ", UTC year: " << utcTime->tm_year << ", UTC month: " << utcTime->tm_mon << ", UTC day: " << utcTime->tm_mday << endl;
Instead of producing the expected result (Friday January 1 2021 5:00 PM), the code snippet above produces the following result:
UTC hh: 9, UTC mm: 0, UTC year: 121, UTC month: 0, UTC day: 1
which is "month 0, day 1, year 121, 9:00 AM". Year and month are fixed after passing utcTime to the mktime() function. After adding the lines
time_t utc_time_t = mktime(utcTime);
cout << ctime(&utc_time_t) << endl;
the output is
Fri Jan 1 09:00:00 2021
Still, the time (hh:mm:ss) is wrong (exactly the same as in the original timezone). Could you please help me figure out the problem with my code? Thank you very much!

Calculating results pro rata over several months with PowerQuery

I am currently stuck on below issue:
I have two tables that I have to work with, one contains financial information for vessels and the other contains arrival and departure time for vessels. I get my data combining multiple excel sheets from different folders:
financialTable
voyageTimeTable
I have to calculate the result for above voyage, and apportion the result over June, July and August for both estimated and updated.
Time in June : 4 hours (20/06/2020 20:00 - 23:59) + 10 days (21/06/2020 00:00 - 30/06/2020 23:59) = 10.1666
Time in July : 31 full days
Time in August: 1 day + 14 hours (02/08/2020 00:00 - 14:00) = 1.5833
Total voyage duration = 10.1666 + 31 + 1.5833 = 42.7499
The result for the "updated" financialItem would be the following:
Result June : 100*(10.1666/42.7499) = 23.7816
Result July : 100*(31/42.7499) = 72.5148
Result August : 100*(1.5833/42.7499) = 3.7036
sum = 100
and then for "estimated" it would be twice of everything above.
This is the format I ideally would like to get:
prorataResultTable
I have to do this for multiple vessels, with multiple timespans and several voyage numbers.
Eagerly awaiting responses, if any. Many thanks in advance.
Brds,
Not sure if you're still looking for an answer, but code below gives me your expected output:
let
financialTable = Table.FromRows({{"A", 1, "profit/loss", 200, 100}}, type table [vesselName = text, vesselNumber = Int64.Type, financialItem = text, estimated = number, updated = number]),
voyageTimeTable = Table.FromRows({{"A", 1, #datetime(2020, 6, 20, 20, 0, 0), #datetime(2020, 8, 2, 14, 0, 0)}}, type table [vesselName = text, vesselNumber = Int64.Type, voyageStartDatetime = datetime, voyageEndDatetime = datetime]),
joined =
let
joined = Table.NestedJoin(financialTable, {"vesselName", "vesselNumber"}, voyageTimeTable, {"vesselName", "vesselNumber"}, "$toExpand", JoinKind.LeftOuter),
expanded = Table.ExpandTableColumn(joined, "$toExpand", {"voyageStartDatetime", "voyageEndDatetime"})
in expanded,
toExpand = Table.AddColumn(joined, "$toExpand", (currentRow as record) =>
let
voyageInclusiveStart = DateTime.From(currentRow[voyageStartDatetime]),
voyageExclusiveEnd = DateTime.From(currentRow[voyageEndDatetime]),
voyageDurationInDays = Duration.TotalDays(voyageExclusiveEnd - voyageInclusiveStart),
createRecordForPeriod = (someInclusiveStart as datetime) => [
inclusiveStart = someInclusiveStart,
exclusiveEnd = List.Min({
DateTime.From(Date.EndOfMonth(DateTime.Date(someInclusiveStart)) + #duration(1, 0, 0, 0)),
voyageExclusiveEnd
}),
durationInDays = Duration.TotalDays(exclusiveEnd - inclusiveStart),
prorataDuration = durationInDays / voyageDurationInDays,
estimated = prorataDuration * currentRow[estimated],
updated = prorataDuration * currentRow[updated],
month = Date.MonthName(DateTime.Date(inclusiveStart)),
year = Date.Year(inclusiveStart)
],
monthlyRecords = List.Generate(
() => createRecordForPeriod(voyageInclusiveStart),
each [inclusiveStart] < voyageExclusiveEnd,
each createRecordForPeriod([exclusiveEnd])
),
toTable = Table.FromRecords(monthlyRecords)
in toTable
),
expanded =
let
dropped = Table.RemoveColumns(toExpand, {"estimated", "updated", "voyageStartDatetime", "voyageEndDatetime"}),
expanded = Table.ExpandTableColumn(dropped, "$toExpand", {"month", "year", "estimated", "updated"})
in expanded
in
expanded
The code tries to:
join financialTable and voyageTimeTable, so that for each vesselName and vesselNumber combination, we know: estimated, updated, voyageStartDatetime and voyageEndDatetime.
generate a list of months for the period between voyageStartDatetime and voyageEndDatetime (which get expanded into new table rows)
for each month (in the list), do all the arithmetic you mention in your question
get rid of some columns (like the old estimated and updated columns)
I recommend testing it with different vesselNames and vesselNumbers from your dataset, just to see if the output is always correct (I think it should be).
You should be able to manually inspect the cells in the $toExpand column (of the toExpand step/expression) to see the nested rows before they get expanded.

how to know which quarter does the current month belongs to ? (in python )

I want to know to which quarter(Q1,Q2,Q3,Q4) does the current month belongs to in python. I'm fetching the current date by importing time module as follows:
import time
print "Current date " + time.strftime("%x")
any idea how to do it ?
Modifying your code, I get this:
import time
month = int(time.strftime("%m")) - 1 # minus one, so month starts at 0 (0 to 11)
quarter = month / 3 + 1 # add one, so quarter starts at 1 (1 to 4)
quarter_str = "Q" + str(quarter) # convert to the "Qx" format string
print quarter_str
Or you could use the bisect module:
import time
import bisect
quarters = range(1, 12, 3) # This defines quarters: Q1 as 1, 2, 3, and so on
month = int(time.strftime("%m"))
quarter = bisect.bisect(quarters, month)
quarter_str = = "Q" + str(quarter)
print quarter_str
strftime does not know about quarters, but you can calculate them from the month:
Use time.localtime to retrieve the current time in the current timezone. This function returns a named tuple with year, month, day of month, hour, minute, second, weekday, day of year, and time zone offset. You will only need the month (tm_mon).
Use the month to calculate the quarter. If the first quarter starts with January and ends with March, the second quarter starts with April and ends with June, etc. then this is as easy as dividing by 4 without remainder and adding 1 (for 1..3 // 4 == 0, 0 + 1 == 1, 4..6 // 4 == 1, 1 + 1 == 2, etc.). If your definition of what a quarter is differs (e.g. companies may choose different start dates for their financial quarters), you have to adjust the calculation accordingly.

decision tree Python with exceptions 2.7

I'm writing a script which calculates the date of Easter for years 1900 - 2099.
The thing is that for 4 certain years (1954, 1981, 2049, and 2076) the formula differs a little bet (namely, the date is off 7 days).
def main():
print "Computes the date of Easter for years 1900-2099.\n"
year = input("The year: ")
if year >= 1900 and year <= 2099:
if year != 2049 != 2076 !=1981 != 1954:
a = year%19
b = year%4
c = year%7
d = (19*a+24)%30
e = (2*b+4*c+6*d+5)%7
date = 22 + d + e # March 22 is the starting date
if date <= 31:
print "The date of Easter is March", date
else:
print "The date of Easter is April", date - 31
else:
if date <= 31:
print "The date of Easter is March", date - 7
else:
print "The date of Easter is April", date - 31 - 7
else:
print "The year is out of range."
main()
Exerything is working well but the 4 years computation.
I'm getting the:
if date <= 31:
UnboundLocalError: local variable 'date' referenced before assignment whenever I'm entering any of the 4 years as input.
You cannot chain a expression like that; chain the tests using and operators or use a not in expression instead:
# and operators
if year != 2049 and year != 2076 and year != 1981 and year != 1954:
# not in expression
if year not in (2049, 2076, 1981, 1954):
The expression year != 2049 != 2076 !=1981 != 1954 means something different, it is interpreted as (((year != 2049) != 2076) !=1981) != 1954 instead; the first test is either True or False, and neither of those two values will ever be equal to any of the other numbers and that branch will always evaluate to False.
You will still get the UnboundLocalError for date though, since your else branch refers to date but it is never set in that branch. When the else branch executes, all Python sees is:
def main():
print "Computes the date of Easter for years 1900-2099.\n"
year = input("The year: ")
if year >= 1900 and year <= 2099:
if False:
# skipped
else:
if date <= 31:
print "The date of Easter is March", date - 7
else:
print "The date of Easter is April", date - 31 - 7
and date is never assigned a value in that case. You need to calculate date separately in that branch still, or move the calculation of the date value out of the if statement altogether; I am not familiar with the calculation of Easter so I don't know what you need to do in this case.