大约有 13,700 项符合查询结果（耗时：0.0396秒） [XML]
How to select rows from a DataFrame based on column values?
...
To select rows whose column value equals a scalar, some_value, use ==:
df.loc[df['column_name'] == some_value]
To select rows whose column value is in an iterable, some_values, use isin:
df.loc[df['column_name'].isin(some_values)]
Combine multiple conditions with &:
d...
MongoDB Many-to-Many Association
...intain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:["4b5783300334000000000aa9","5783300334000000000aa943","6c6793300334001000000006"]
}
and set up the roles like:
{_id:"6c6793300334001000000006"
,rolename:"Eng...
How to delete an object by id with entity framework
...
I am using the following code in one of my projects:
using (var _context = new DBContext(new DbContextOptions<DBContext>()))
{
try
{
_context.MyItems.Remove(new MyItem() { MyItemId = id });
await _context.SaveChangesAsync();
}
...
How to Free Inode Usage?
...ries that contain lots of files, this script may help:
#!/bin/bash
# count_em - count files in all subdirectories under current directory.
echo 'echo $(ls -a "$1" | wc -l) $1' >/tmp/count_em_$$
chmod 700 /tmp/count_em_$$
find . -mount -type d -print0 | xargs -0 -n1 /tmp/count_em_$$ | sort -n
rm ...
Call a “local” function within module.exports from another function in module.exports?
... a direct answer to the question
– Kermit_ice_tea
Mar 3 '16 at 23:24
8
...
In Python, when should I use a function instead of a method?
... as cars. You mention a duck, so let's go with that.
class duck:
def __init__(self):pass
def eat(self, o): pass
def crap(self) : pass
def die(self)
....
In the context of the "objects are real things" analogy, it is "correct" to add a class method for anything which the obje...
How are echo and print different in PHP? [duplicate]
...
From:
http://web.archive.org/web/20090221144611/http://faqts.com/knowledge_base/view.phtml/aid/1/fid/40
Speed. There is a difference between the two, but speed-wise it
should be irrelevant which one you use. echo is marginally faster
since it doesn't set a return value if you really want to ge...
How do I write output in same place on the console?
...
#kinda like the one above but better :P
from __future__ import print_function
from time import sleep
for i in range(101):
str1="Downloading File FooFile.txt [{}%]".format(i)
back="\b"*len(str1)
print(str1, end="")
sleep(0.1)
print(back, end="")
...
What is the purpose of “return await” in C#?
...ss, in first case you should return foo.DoAnotherThingAsync().ContinueWith(_ => foo.Dispose());
– ghord
Sep 23 '14 at 8:58
7
...
How to properly URL encode a string in PHP?
...owever, you shouldn't need to use urldecode() on variables that appear in $_POST and $_GET.
share
|
improve this answer
|
follow
|
...