大约有 40,000 项符合查询结果（耗时：0.0654秒） [XML]
“:” (colon) in C struct - what does it mean? [duplicate]
... can only be declared as part of a structure. The address-of operator
(&) cannot be applied to bit-field components.
Unnamed bit fields cannot be referenced, and their contents at run
time are unpredictable. They can be used as "dummy" fields, for
alignment purposes. An unnamed bit f...
Convert floating point number to a certain precision, and then copy to string
I have a floating point number, say 135.12345678910 . I want to concatenate that value to a string, but only want 135.123456789 . With print, I can easily do this by doing something like:
...
How to send email from Terminal?
... for help.
You will need to set SMTP up:
http://hints.macworld.com/article.php?story=20081217161612647
See also:
http://www.mactricksandtips.com/2008/09/send-mail-over-your-network.html
Eg:
mail -s "hello" "example@example.com" <<EOF
hello
world
EOF
This will send an email to example@example....
你需要TrustedInstaller提供的权限才能对此文件进行更改 - 更多技术 - 清泛...
...限"
[HKEY_CLASSES_ROOT\*\shell\runas\command]
@="cmd.exe /c takeown /f \"%1\" && icacls \"%1\" /grant administrators:F"
"IsolatedCommand"="cmd.exe /c takeown /f \"%1\" && icacls \"%1\" /grant administrators:F"
[HKEY_CLASSES_ROOT\Directory\shell\runas]
@="获取TrustedInstaller权限"
"NoW...
How do I make a branch point at a specific commit? [duplicate]
...
You can make master point at 1258f0d0aae this way:
git checkout master
git reset --hard 1258f0d0aae
But you have to be careful about doing this. It may well rewrite the history of that branch. That would create problems if you have published it and other ...
Ruby on Rails: How do I add placeholder text to a f.text_field?
How can I add placeholder text to my f.text_field fields so that the text comes pre-written by default, and when a user click inside the fields, the text goes away - allowing the user to type in the new text?
...
Do c++11 lambdas capture variables they don't use?
...le in the lambda expression, then the variable is not captured. In your example, my_huge_vector is not captured.
Per C++11 §5.1.2[expr.prim.lambda]/11:
If a lambda-expression has an associated capture-default and its compound-statement odr-uses this or a variable with automatic storage duration ...
Filter rows which contain a certain string
...n easily extend to more than one column.
Below also a solution with filter_all in order to find the string in any column,
using diamonds as example, looking for the string "V"
library(tidyverse)
String in only one column
# for only one column... extendable to more than one creating a column list in...
Get path from open file in Python
If I have an opened file, is there an os call to get the complete path as a string?
4 Answers
...
pandas: multiple conditions while indexing data frame - unexpected behavior
..., not in terms of what you want to drop. For df1:
df1 = df[(df.a != -1) & (df.b != -1)]
You're saying "keep the rows in which df.a isn't -1 and df.b isn't -1", which is the same as dropping every row in which at least one value is -1.
For df2:
df2 = df[(df.a != -1) | (df.b != -1)]
You're...