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Check if key exists and iterate the JSON array using Python
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If all you want is to check if key exists or not
h = {'a': 1}
'b' in h # returns False
If you want to check if there is a value for key
h.get('b') # returns None
Return a default value if actual value is missing
h.get('b'...
This app won't run unless you update Google Play Services (via Bazaar)
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UPDATE
The Google maps API v2 is now installed on the latest Google system images (api:19 ARM or x86).
So your application should just work with the new images. There is no need to install these files.
I've been trying to run an Android Google Maps V2 application u...
py2exe - generate single executable file
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PyInstaller will create a single .exe file with no dependencies; use the --onefile option. It does this by packing all the needed shared libs into the executable, and unpacking them before it runs, just as you describe (EDIT: py2ex...
What's wrong with overridable method calls in constructors?
...ohibit it:
There are a few more restrictions that a class must obey to allow inheritance. Constructors must not invoke overridable methods, directly or indirectly. If you violate this rule, program failure will result. The superclass constructor runs before the subclass constructor, so the overr...
Why would I ever use push_back instead of emplace_back?
...ob is to generate the code you wrote. The optimizing compiler's job is actually to generate the code you would have written if you were an expert on platform-specific optimizations and did not care about maintainability, just performance.
The actual difference between these two statements is that t...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...
Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...定义的值。如：
foo = $(bar)
bar = $(ugh)
ugh = Huh?
all:
echo $(foo)
我们执行“make all”将会打出变量$(foo)的值是“Huh?”（ $(foo)的值是$(bar)，$(bar)的值是$(ugh)，$(ugh)的值是“Huh?”）可见，变量是可以使用后面的变量来...