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float64 with pandas to_csv
...mvent this problem, I recommend you create another CSV file which contains all figures as integers, for example multiplying by 100, 1000 or other factor which turns out to be convenient. Inside your application, read the CSV file as usual and you will get those integer figures back. Then convert tho...
Difference between method and function in Scala
..., no instance - with a method type. As mentioned above, a Method Value actually has a Function Type. A method type is a def declaration - everything about a def except its body.
Value Declarations and Definitions and Variable Declarations and Definitions are val and var declarations, including both...
Python - abs vs fabs
...e about complex numbers. Out of interest, what other classes of things can __builtin__.abs() be successfully applied to?
– NPE
May 27 '12 at 7:31
...
fstream默认不支持中文路径和输出整数带逗号的解决办法 - C/C++ - 清泛网 -...
... i << "/n"; //输出带逗号
outfile.close();
setlocale( LC_ALL, "C" ); //恢复全局locale，如果不恢复，可能导致cout无法输出中文
}
创建文件成功，在程序的“测试”文件下出现个test.txt文件。需要注意的是最后需要调用setlocale( ...
MySQL和MongoDB设计实例进行对比 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...查询：
db.getCollection("mobiles").find({
"params": {
$all: [
{$elemMatch: {"name": "待机时间", "value": {$gt: 100}}},
{$elemMatch: {"name": "外观设计", "value": "直板"}}
]
}
});
注：查询中用到的$all，$elemMatch等高...
Linux MySql编译安装 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...d mysql
useradd -g mysql mysql
#开始编译安装
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
-DMYSQL_UNIX_ADDR=/tmp/mysql.sock \
-DDEFAULT_CHARSET=utf8 \
-DDEFAULT_COLLATION=utf8_general_ci \
-DWITH_EXTRA_CHARSETS=all \
-DWITH_MYISAM_STORAGE_ENGINE=1 \
-DWITH_INNOBASE_STORAGE_ENGIN...
Do declared properties require a corresponding instance variable?
...
In your interface, you can formally declare an instance variable between the braces, or via @property outside the braces, or both. Either way, they become attributes of the class. The difference is that if you declare @property, then you can implement usin...
count(*) vs count(column-name) - which is more correct? [duplicate]
...
COUNT(*) counts all rows
COUNT(column) counts non-NULLs only
COUNT(1) is the same as COUNT(*) because 1 is a non-null expressions
Your use of COUNT(*) or COUNT(column) should be based on the desired output only.
...
Difference between JSON.stringify and JSON.parse
...pt object into JSON text and stores that JSON text in a string, eg:
var my_object = { key_1: "some text", key_2: true, key_3: 5 };
var object_as_string = JSON.stringify(my_object);
// "{"key_1":"some text","key_2":true,"key_3":5}"
typeof(object_as_string);
// "string"
JSON.parse turns a...
Retrieve database or any other file from the Internal Storage using run-as
...nly copy DBs from the Debug variant of your app. If this happens, just install the debug variant and try the command again. Hope this helps someone.
– Aonghus Shortt
Apr 14 '17 at 18:02
...