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Use 'import module' or 'from module import'?
...ur use of it. Here are some points to help you decide.
import module
Pros:
Less maintenance of your import statements. Don't need to add any additional imports to start using another item from the module
Cons:
Typing module.foo in your code can be tedious and redundant (tedium can be minimi...
Import multiple csv files into pandas and concatenate into one DataFrame
...like an old fashioned aka manual way of doing things, esp. as the Hapood ecosystem has growing list of tools where you can perform sql queries directly on many different directories containing different file types (csv, json, txt, databases) as if it was one data source. There must be something si...
Relative imports in Python 3
... the relative import...
from .mymodule import as_int
The way you're supposed to run it is...
python3 -m mypackage.myothermodule
...but it's somewhat verbose, and doesn't mix well with a shebang line like #!/usr/bin/env python3.
The simplest fix for this case, assuming the name mymodule is glo...
Library not loaded: libmysqlclient.16.dylib error when trying to run 'rails server' on OS X 10.6 wit
...
For those who are curious what's going on, this command makes a symbolic link from the second location to the first. When the gem looks for the MySQL client library under /usr/lib, that link will resolve to the location where it's ...
Do on-demand Mac OS X cloud services exist, comparable to Amazon's EC2 on-demand instances? [closed]
Amazon's EC2 service offers a variety of Linux and Windows OS choices, but I haven't found a service offering a similar "rent by the hour" service for a remote Mac OS X virtual machine. Does such a service exist? (iCloud looks to be just a data storage service, rather than a service allowing remot...
Redirecting stdout to “nothing” in python
...
Cross-platform:
import os
import sys
f = open(os.devnull, 'w')
sys.stdout = f
On Windows:
f = open('nul', 'w')
sys.stdout = f
On Linux:
f = open('/dev/null', 'w')
sys.stdout = f
...
How to hide output of subprocess in Python 2.7
...
Redirect the output to DEVNULL:
import os
import subprocess
FNULL = open(os.devnull, 'w')
retcode = subprocess.call(['echo', 'foo'], stdout=FNULL, stderr=subprocess.STDOUT)
It is effectively the same as running this shell command:
retcode = os.system("echo 'fo...
Getting file size in Python? [duplicate]
...
Use os.path.getsize(path) which will
Return the size, in bytes, of path. Raise OSError if the file does not exist or is inaccessible.
import os
os.path.getsize('C:\\Python27\\Lib\\genericpath.py')
Or use os.stat(path).st_...
Get last n lines of a file, similar to tail
...ctually accurate, you make the block size 2048 and you'll tail 20 lines almost immediately.
Also, I don't burn a lot of brain calories trying to finesse alignment with physical OS blocks. Using these high-level I/O packages, I doubt you'll see any performance consequence of trying to align on OS b...
error C2662: “Screen::move”: 不能将“this”指针从“const Screen”转...
...ursor = row + c;
return *this;
}
const Screen& Screen::display(std::ostream& os) const
{
os << contents << '\n';
return *this;
}
//main中处理
myScreen.display(cout).move(4,0).set('#').display(cout);
解决办法：通过返回调用函数的对象的引用，可以将一些...