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A numeric string as array key in PHP
Is it possible to use a numeric string like "123" as a key in a PHP array, without it being converted to an integer?
11 A...
What is the difference between parseInt() and Number()?
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typeof parseInt("123") => number
typeof Number("123") => number
typeof new Number("123") => object (Number primitive wrapper object)
first two will give you better performance as it returns a primitive instead of an object.
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How to overcome TypeError: unhashable type: 'list'
... else:
d[key] = [value]
print d
# {'AAA': ['111', '112'], 'AAC': ['123'], 'AAB': ['111']}
Note that if you are using Python 3.x, you'll have to make a minor adjustment to get it work properly. If you open the file with rb, you'll need to use line = line.split(b'x') (which makes sure you ar...
Python-equivalent of short-form “if” in C++ [duplicate]
Is there a way to write this C/C++ code in Python?
a = (b == true ? "123" : "456" )
4 Answers
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Fastest check if row exists in PostgreSQL
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How about simply:
select 1 from tbl where userid = 123 limit 1;
where 123 is the userid of the batch that you're about to insert.
The above query will return either an empty set or a single row, depending on whether there are records with the given userid.
If this turns o...
How to pass an array within a query string?
...a comma separated list of items:
let data = {
str: 'abc',
arr: ['abc', 123]
}
new URLSearchParams(data).toString(); // ?str=abc&arr=abc,123
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Difference between filter and filter_by in SQLAlchemy
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Be careful when using .filter. a query like id=12345, query(users).filter(id == id) will not filter on users.id. Instead, it will evaluate id == id as True and return all users. You need to use .filter(users.id == id) (as demoed above). I made this mistake earlier today.
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How to Implement Custom Table View Section Headers and Footers with Storyboard
...bel to the header cell
set the tag of the label to a specific number (e.g. 123)
In your tableView:viewForHeaderInSection: method get the label by calling:
UILabel *label = (UILabel *)[headerView viewWithTag:123];
Now you can use the label to set a new title:
[label setText:@"New Titl...
Summarizing multiple columns with dplyr? [duplicate]
...brary(dplyr)
library(purrrlyr)
library(data.table)
library(bench)
set.seed(123)
n <- 10000
df <- data.frame(
a = sample(1:5, n, replace = TRUE),
b = sample(1:5, n, replace = TRUE),
c = sample(1:5, n, replace = TRUE),
d = sample(1:5, n, replace = TRUE),
grp = sample(1:3, n, replac...
How do I check if a C++ std::string starts with a certain string, and convert a substring to an int?
...only match at that position or earlier. For example:
std::string test = "0123123";
size_t match1 = test.rfind("123"); // returns 4 (rightmost match)
size_t match2 = test.rfind("123", 2); // returns 1 (skipped over later match)
size_t match3 = test.rfind("123", 0); // returns std::string::npos (i...