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How to delete last item in list?
...icing notation to keep everything except the last item:
record = record[:-1]
But a better way is to delete the item directly:
del record[-1]
Note 1: Note that using record = record[:-1] does not really remove the last element, but assign the sublist to record. This makes a difference if you ru...
How to use background thread in swift?
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Adding gif image in an ImageView in android
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Is there a common Java utility to break a list into batches?
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how to concatenate two dictionaries to create a new one in Python? [duplicate]
...nate the items and call dict on the resulting list:
$ python -mtimeit -s'd1={1:2,3:4}; d2={5:6,7:9}; d3={10:8,13:22}' \
'd4 = dict(d1.items() + d2.items() + d3.items())'
100000 loops, best of 3: 4.93 usec per loop
Fastest: exploit the dict constructor to the hilt, then one update:
$ python -mtim...
Is there a difference between using a dict literal and a dict constructor?
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Update multiple rows in same query using PostgreSQL
...izable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
where c.column_b = t.column_b;
You can add as many columns as you like:
update test as t set
column_a = c.column_a,
column_c = c.column_c
from (values
('12...
error: default argument given for parameter 1
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