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Pandas - How to flatten a hierarchical index in columns
... would be to set the columns to the top level:
df.columns = df.columns.get_level_values(0)
Note: if the to level has a name you can also access it by this, rather than 0.
.
If you want to combine/join your MultiIndex into one Index (assuming you have just string entries in your columns) you cou...
Forward an invocation of a variadic function in C
...
If you don't have a function analogous to vfprintf that takes a va_list instead of a variable number of arguments, you can't do it. See http://c-faq.com/varargs/handoff.html.
Example:
void myfun(const char *fmt, va_list argp) {
vfprintf(stderr, fmt, argp);
}
...
Regex Named Groups in Java
...> TEST
matcher.name(1) ==> login
Replace
matcher.replaceAll("aaaaa_$1_sssss_$2____") ==> aaaaa_TEST_sssss_123____
matcher.replaceAll("aaaaa_${login}_sssss_${id}____") ==> aaaaa_TEST_sssss_123____
(extract from the implementation)
public final class Pattern
implements java.io...
How do I get the path to the current script with Node.js?
...r looking through the documentation again. What I was looking for were the __filename and __dirname module-level variables.
__filename is the file name of the current module. This is the resolved absolute path of the current module file. (ex:/home/kyle/some/dir/file.js)
__dirname is the directory ...
How do I access the request object or any other variable in a form's clean() method?
... no reason to do it this way.
A much better way is to override the form's __init__ method to take an extra keyword argument, request. This stores the request in the form, where it's required, and from where you can access it in your clean method.
class MyForm(forms.Form):
def __init__(self, *...
Dictionaries and default values
...collections import defaultdict
a = defaultdict(lambda: "default", key="some_value")
a["blabla"] => "default"
a["key"] => "some_value"
You can pass any ordinary function instead of lambda:
from collections import defaultdict
def a():
return 4
b = defaultdict(a, key="some_value")
b['absent...
App Inventor 2 实现上传文件到服务器全方案总结 · App Inventor 2 中文网
...
php服务端代码参考：
python服务端参考：
from flask_restful import Api, Resource
from flask import Flask, request
app = Flask(__name__)
api = Api(app)
# 这边的类名是自己定义的
class receive_pic(Resource):
def put(self):
#接收二进制流保存为图...
Error in finding last used cell in Excel with VBA
...on.CountA(.Cells) <> 0 Then
lastrow = .Cells.Find(What:="*", _
After:=.Range("A1"), _
Lookat:=xlPart, _
LookIn:=xlFormulas, _
SearchOrder:=xlByRows, _
SearchDirection:=xlPrevio...
How to delete (not cut) in Vim?
...
Use the "black hole register", "_ to really delete something: "_d.
Use "_dP to paste something and keep it available for further pasting.
For the second question, you could use <C-o>dw. <C-o> is used to execute a normal command without leaving ...
Programmatically generate video or animated GIF in Python?
...longer movies, use the streaming approach:
import imageio
with imageio.get_writer('/path/to/movie.gif', mode='I') as writer:
for filename in filenames:
image = imageio.imread(filename)
writer.append_data(image)
...