大约有 5,400 项符合查询结果（耗时：0.0273秒） [XML]
get list of pandas dataframe columns based on data type
...1 2.3456 c d 78
[1 rows x 5 columns]
>>> df.dtypes
A int64
B float64
C object
D object
E int64
dtype: object
>>> g = df.columns.to_series().groupby(df.dtypes).groups
>>> g
{dtype('int64'): ['A', 'E'], dtype('float64'): ['B'], dtype('O'): ['C', 'D'...
Why does the C preprocessor interpret the word “linux” as the constant “1”?
...efine __CHAR_BIT__ 8
#define __UINT8_MAX__ 255
#define __WINT_MAX__ 2147483647
#define __ORDER_LITTLE_ENDIAN__ 1234
#define __SIZE_MAX__ 18446744073709551615UL
#define __WCHAR_MAX__ 2147483647
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_1 1
#define __GCC_HAVE_SYNC_COMPARE_AND_SWAP_2 1
#define __GCC_HAV...
What is the argument for printf that formats a long?
...
647
Put an l (lowercased letter L) directly before the specifier.
unsigned long n;
long m;
pri...
Where Is Machine.Config?
...32-bit
%windir%\Microsoft.NET\Framework\[version]\config\machine.config
64-bit
%windir%\Microsoft.NET\Framework64\[version]\config\machine.config
[version] should be equal to v1.0.3705, v1.1.4322, v2.0.50727 or v4.0.30319.
v3.0 and v3.5 just contain additional assemblies to v2.0.50727 so the...
How to install Java SDK on CentOS?
...
164
The following command will return a list of all packages directly related to Java. They will be...
Hash function that produces short hashes?
...
@erasmospunk: encoding with base64 does nothing for collision resistance, since if hash(a) collides with hash(b) then base64(hash(a)) also collides with base64(hash(b)).
– Greg Hewgill
Nov 12 '13 at 18:37
...
Why do x86-64 systems have only a 48 bit virtual address space?
...facturers took a shortcut. They use an instruction set which allows a full 64-bit address space, but current CPUs just only use the lower 48 bits. The alternative was wasting transistors on handling a bigger address space which wasn't going to be needed for many years.
So once we get near the 48-bi...
Best way to create unique token in Rails?
...ken
self.token = loop do
random_token = SecureRandom.urlsafe_base64(nil, false)
break random_token unless ModelName.exists?(token: random_token)
end
end
end
Edit:
@kain suggested, and I agreed, to replace begin...end..while with loop do...break unless...end in this answer b...
Android Studio installation on Windows 7 fails, no JDK found
...
+1 This MOSTLY worked for me. I am running 64 bit windows and JDK 1.7.0. I tried adding both JDK_HOME and JAVA_HOME with "c:\Program Files\Java\jdk1.7.0\". It still would not load. However, I capitalized the "C" and removed the trailing slash and it works now: "C:\Pr...
Openssl is not recognized as an internal or external command
...bin\openssl.exe" sha1 -binary | "C:\Users\abc\openssl\bin\openssl.exe" base64
Remember, path that you will enter will be the path where you have installed the openssl...hope this helps..:-)
Edit:
you can download openssl for windows 32 and 64 bit from the respective links below:
OpenSSL for 64 Bits...