大约有 43,000 项符合查询结果（耗时：0.0230秒） [XML]
How to select rows from a DataFrame based on column values?
..., 3000, 10000, 30000],
dtype=float
)
for j in res.columns:
d = pd.concat([df] * j, ignore_index=True)
for i in res.index:a
stmt = '{}(d)'.format(i)
setp = 'from __main__ import d, {}'.format(i)
res.at[i, j] = timeit(stmt, setp, number=50)
Special Timing
Looki...
How to trim a string to N chars in Javascript?
...ted, i.e. it will return the string up to it's end if there are not enough characters for the given end!
– centic
Feb 11 '15 at 14:53
...
What are the mechanics of short string optimization in libc++?
...th:
1 bit goes to the long/short flag.
7 bits goes to the size.
Assuming char, 1 byte goes to the trailing null (libc++ will always store a trailing null behind the data).
This leaves 3 words minus 2 bytes to store a short string (i.e. largest capacity() without an allocation).
On a 32 bit mach...
Find the nth occurrence of substring in a string
... risk here of course is that the string to search for will contain special characters that will cause the regex to do something you didn't want. Using re.escape should solve this.
– Mark Byers
Dec 10 '09 at 21:43
...
Split string on the first white space occurrence
...lit(/\s(?=\S+$)/).reverse().map(reverse)
or maybe
re = /^\S+\s|.*/g;
[].concat.call(re.exec(str), re.exec(str))
2019 update: as of ES2018, lookbehinds are supported:
str = "72 tocirah sneab"
s = str.split(/(?<=^\S+)\s/)
console.log(s)
...
How to use the same C++ code for Android and iOS?
...laration that receives the desired text:
#include <iostream>
const char *concatenateMyStringWithCppString(const char *myString);
And the CPP implementation:
#include <string.h>
#include "Core.h"
const char *CPP_BASE_STRING = "cpp says hello to %s";
const char *concatenateMyStringW...
Replacing column values in a pandas DataFrame
...'] could be 'male', 'female' or 'neutral', do something like this:
w = pd.concat([w, pd.get_dummies(w['female'], drop_first = True)], axis = 1])
w.drop('female', axis = 1, inplace = True)
Then you are left with two new columns giving you the dummy coding of 'female' and you got rid of the column ...
When is CRC more appropriate to use than MD5/SHA1?
... inappropriate CRC hashes are for hash tables. It also explains the actual characteristics of the algorithm. The study also includes evaluation of other hash algorithms and is a good reference to keep.
The relevant conclusion on CRC for hashes:
CRC32 was never intended for hash table use. There...
How do I get the path of a process in Unix / Linux
...swers were specific to linux.
If you need also unix, then you need this:
char * getExecPath (char * path,size_t dest_len, char * argv0)
{
char * baseName = NULL;
char * systemPath = NULL;
char * candidateDir = NULL;
/* the easiest case: we are in linux */
size_t buff_len;
...
Converting string to title case
I have a string which contains words in a mixture of upper and lower case characters.
23 Answers
...