大约有 44,000 项符合查询结果（耗时：0.0267秒） [XML]
How can I get the concatenation of two lists in Python without modifying either one? [duplicate]
In Python, the only way I can find to concatenate two lists is list.extend , which modifies the first list. Is there any concatenation function that returns its result without modifying its arguments?
...
Changing the default folder in Emacs
...s works on MacOS too. I added this to my .emacs: (setq default-directory (concat (getenv "HOME") "/"))
– vy32
Dec 21 '13 at 15:46
...
How can I split a string with a string delimiter? [duplicate]
...new[] { "is Marco and" }, StringSplitOptions.None);
If you have a single character delimiter (like for instance ,), you can reduce that to (note the single quotes):
string[] tokens = str.Split(',');
share
|
...
C# Stream流使用总结 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...取流
TextWriter textWriter = new StringWriter();//初始化写入流
char[] c=new char[4096];
int chars = 0;
while ((chars = textReader.Read(c, 0, 4096)) > 0)//把流中数据写入到字符数组中
{
textWriter.Write(c, 0, 4096);//从字符数组中读取流
}
string str= textWrit...
Why does Path.Combine not properly concatenate filenames that start with Path.DirectorySeparatorChar
...? "path1" : "path2");
Contract.EndContractBlock();
CheckInvalidPathChars(path1);
CheckInvalidPathChars(path2);
return CombineNoChecks(path1, path2);
}
internal static string CombineNoChecks(string path1, string path2)
{
if (path2.Length == 0)
return path1;
if (path...
How do I get a list of all the duplicate items using pandas in python?
...ds so many times. I prefer method #2: groupby on the ID.
>>> pd.concat(g for _, g in df.groupby("ID") if len(g) > 1)
ID ENROLLMENT_DATE TRAINER_MANAGING TRAINER_OPERATOR FIRST_VISIT_DATE
6 11795 3-Jul-12 0649597-White River VT 0649597-White River VT ...
Traverse all the Nodes of a JSON Object Tree with JavaScript
...ypeOf(value) === Object.prototype) {
traverse(value, callback, trail.concat(key))
} else {
callback.call(obj, key, value, trail)
}
})
}
traverse({a: {b: {c: {d: 1}}, e: {f: 2}}}, function (key, value, trail) {
console.log(arguments)
})
...
Difference between size_t and unsigned int?
...int is not the only unsigned integer type. size_t could be any of unsigned char, unsigned short, unsigned int, unsigned long or unsigned long long, depending on the implementation.
Second question is that size_t and unsigned int are interchangeable or not and if not then why?
They aren't inter...
How to convert std::string to lower case?
...ideal anyway as use with a std::string would require iterating over each character.
25 Answers
...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...ER(x,y)
#define NAME(fun) EVALUATOR(fun, VARIABLE)
extern void NAME(mine)(char *x);
$ gcc -E xx.c
# 1 "xx.c"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "xx.c"
extern void mine_3(char *x);
$
Two levels of indirection
In a comment to another answer, Cade Roux asked why this needs t...