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capturing self strongly in this block is likely to lead to a retain cycle
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Good answer, but I take small issue with you saying: “you can't refer to self or properties on self from within a block that will be strongly retained by self.” This is not strictly true. Please see my answer below. Better to say, “you must take...
Flatten nested dictionaries, compressing keys
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Basically the same way you would flatten a nested list, you just have to do the extra work for iterating the dict by key/value, creating new keys for your new dictionary and creating the dictionary at final step.
import collectio...
Cannot issue data manipulation statements with executeQuery()
In MySQL I have two tables, tableA and tableB . I am trying to execute two queries:
10 Answers
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What is the difference between '>' and a space in CSS selectors?
...e child selector is not supported by IE 6 and lower. A great compatibility table is here.
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How can I output a UTF-8 CSV in PHP that Excel will read properly?
...le Doc's Spreadsheet have no issues with UTF-8 files with commas.
See the table in this question for what works and doesn't work for Unicode CSV files in Excel
As a side note, I might add that if you are using Composer, you should have a look at adding League\Csv to your requires. League\Csv has...
How do I analyze a program's core dump file with GDB when it has command-line parameters?
...xt_ptr = "string in text segment";
(void)argv;
mmap_ptr = (char *)malloc(sizeof(data_ptr) + 1);
strcpy(mmap_ptr, data_ptr);
mmap_ptr[10] = 'm';
mmap_ptr[11] = 'm';
mmap_ptr[12] = 'a';
mmap_ptr[13] = 'p';
printf("text addr: %p\n", text_ptr);
printf("data addr: %p\n...
What does the line “#!/bin/sh” mean in a UNIX shell script?
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When you try to execute a program in unix (one with the executable bit set), the operating system will look at the first few bytes of the file. These form the so-called "magic number", which can be used to decide the format of the program and how to execute it.
#! corresponds to the ...
Representing graphs (data structure) in Python
...f._graph[node2].add(node1)
def remove(self, node):
""" Remove all references to node """
for n, cxns in self._graph.items(): # python3: items(); python2: iteritems()
try:
cxns.remove(node)
except KeyError:
pass
tr...
Remove NA values from a vector
...idiom instead:
d <- d[!is.na(d)]
A final note: Other functions (e.g. table(), lm(), and sort()) have NA-related arguments that use different names (and offer different options). So if NA's cause you problems in a function call, it's worth checking for a built-in solution among the function's a...
Can modules have properties the same way that objects can?
...s? When I put this code in one file x.py and import it from another, then calling x.y results in AttributeError: 'NoneType' object has no attribute 'c', since _M somehow has value None...
– Stephan202
May 19 '09 at 1:35
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