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Getting image dimensions without reading the entire file
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106
Your best bet as always is to find a well tested library. However, you said that is difficult, ...
float64 with pandas to_csv
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df.to_csv('pandasfile.csv', float_format='%.3f')
or, if you don't want 0.0001 to be rounded to zero:
df.to_csv('pandasfile.csv', float_format='%g')
will give you:
Bob,0.085
Alice,0.005
in your output file.
For an explanation of %g, see Format Specification Mini-Language.
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Ternary operator is twice as slow as an if-else block?
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10 Answers
10
Active
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Can PostgreSQL index array columns?
... CREATE TABLE "Test"("Column1" int[]);
INSERT INTO "Test" VALUES ('{10, 15, 20}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Column1");
-- To enforce index usage because we have only 2 records for this test...
SET enable_seqscan ...
In Python, how do I convert all of the items in a list to floats?
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470
[float(i) for i in lst]
to be precise, it creates a new list with float values. Unlike the map...
Make Iframe to fit 100% of container's remaining height
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Update in 2019
TL;DR: Today the best option is the last one in this answer - flexbox. Everything supports it nicely and has for years. Go for that and don't look back. The rest of this answer is left for historical reasons.
The tric...
The most efficient way to implement an integer based power function pow(int, int)
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answered Sep 19 '08 at 12:54
Elias YarrkovElias Yarrkov
3,99311 gold badge1414 silver badges66 bronze badges
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How to print a string in fixed width?
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EDIT 2013-12-11 - This answer is very old. It is still valid and correct, but people looking at this should prefer the new format syntax.
You can use string formatting like this:
>>> print '%5s' % 'aa'
aa
>>>...
Ruby max integer
...ts (integers small enough to store in a single machine word), you can call 0.size to get the number of bytes. I would guess it should be 4 on 32-bit builds, but I can't test that right now. Also, the largest Fixnum is apparently 2**30 - 1 (or 2**62 - 1), because one bit is used to mark it as an inte...
C# Double - ToString() formatting with two decimal places but no rounding
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210
I use the following:
double x = Math.Truncate(myDoubleValue * 100) / 100;
For instance:
If t...