大约有 7,000 项符合查询结果(耗时:0.0237秒) [XML]

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Access nested dictionary items via a list of keys?

... _element = _element[key] _element[keys[-1]] = value example = {"foo": { "bar": { "baz": "ok" } } } keys = ['foo', 'bar'] nested_set(example, "yay", *keys) print(example) Output {'foo': {'bar': 'yay'}} share ...
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How to put multiple statements in one line?

...of simple statements, separated by semi-colon: for i in range(10): print "foo"; print "bar" But as soon as you add a construct that introduces an indented block (like if), you need the line break. Also, for i in range(10): print "i equals 9" if i==9 else None is legal and might approximate wha...
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Programmatically select text in a contenteditable HTML element?

...AllRanges(); sel.addRange(range); } var el = document.getElementById("foo"); selectElementContents(el); share | improve this answer | follow | ...
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Using emit vs calling a signal as if it's a regular function in Qt

...ou can look at by inspecting the C++ code generated by moc. For example a foo signal with no parameters generates this member function: void W::foo() { QMetaObject::activate(this, &staticMetaObject, 0, 0); } And the code emit foo(); is pre-processed to simply foo(); emit is defined in Q...
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WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT

...t new data, new constraints. If you disable a constraint with ALTER TABLE foo NOCHECK CONSTRAINT fk_b and then re-enable it with ALTER TABLE foo CHECK CONSTRAINT fk_b it doesn't verify the constraint. ALTER TABLE foo WITH CHECK CHECK CONSTRAINT fk_b is necessary in order to have the data verified....
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How can I use “sizeof” in a preprocessor macro?

...macro: /* * Simple compile time assertion. * Example: CT_ASSERT(sizeof foo <= 16, foo_can_not_exceed_16_bytes); */ #define CT_ASSERT(exp, message_identifier) \ struct compile_time_assertion { \ char message_identifier : 8 + !(exp); \ } For example in comment MSVC tells some...
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Why are empty catch blocks a bad idea? [closed]

...ed. In Python you often see this kind of construction: try: result = foo() except ValueError: result = None So it might be OK (depending on your application) to do: result = bar() if result == None: try: result = foo() except ValueError: pass # Python pass is equ...
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Can PostgreSQL index array columns?

...e to index the individual array elements. For example: CREATE TABLE test (foo int[]); INSERT INTO test VALUES ('{1,2,3}'); INSERT INTO test VALUES ('{4,5,6}'); CREATE INDEX test_index on test ((foo[1])); SET enable_seqscan TO off; EXPLAIN ANALYZE SELECT * from test WHERE foo[1]=1; ...
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Please explain some of Paul Graham's points on Lisp

...as str]) ;; this is the interesting bit: (println (str/replace-re #"\d+" "FOO" "a123b4c56")) This snippet of Clojure code prints out aFOObFOOcFOO. Note that Clojure arguably does not fully satisfy the fourth point on your list, since read-time is not really open to user code; I will discuss what i...
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How to get the name of a function in Go?

...ion: package main import ( "fmt" "reflect" "runtime" ) func foo() { } func GetFunctionName(i interface{}) string { return runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name() } func main() { // This will print "name: main.foo" fmt.Println("name:", GetFunctionName(foo))...