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How to delete the contents of a folder?
...
import os, shutil
folder = '/path/to/folder'
for filename in os.listdir(folder):
file_path = os.path.join(folder, filename)
try:
if os.path.isfile(file_path) or os.path.islink(file_path):
os.unlink(file_p...
Remove duplicated rows using dplyr
...ction for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_nu...
Checking if a string can be converted to float in Python
... ------------
print(isfloat("")) False
print(isfloat("1234567")) True
print(isfloat("NaN")) True nan is also float
print(isfloat("NaNananana BATMAN")) False
print(isfloat("123.456")) True
print(isfloat("123.E4")) ...
How to refer to relative paths of resources when working with a code repository
We are working with a code repository which is deployed to both Windows and Linux - sometimes in different directories. How should one of the modules inside the project refer to one of the non-Python resources in the project (CSV files, etc.)?
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第一个Hello,OS World操作系统 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
第一个Hello,OS World操作系统hello_os_word_my_first_os操作系统并非我们想象中的深不可测、遥不可及，只要你对它感兴趣并随我一起动手实践，你也能开发出属于自己的os。本文通过一个最简单的os，完成Hello, OS World文字的输出来演示os...
How do I get the full path of the current file's directory?
...ute()
Python 2 and 3
For the directory of the script being run:
import os
os.path.dirname(os.path.abspath(__file__))
If you mean the current working directory:
import os
os.path.abspath(os.getcwd())
Note that before and after file is two underscores, not just one.
Also note that if you ar...
What does the “yield” keyword do?
...one, etc. And generators return... well that's where yield comes in:
def f123():
yield 1
yield 2
yield 3
for item in f123():
print item
Instead of yield statements, if you had three return statements in f123() only the first would get executed, and the function would exit. But f1...
How to get only the last part of a path in Python?
In Python, suppose I have a path like this:
9 Answers
9
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微软VS苹果 桌面操作系统的终极一战 - 创意 - 清泛网 - 专注C/C++及内核技术
... 桌面操作系统的终极一战苹果将在九月份推出正式版的OS X El Capitan。虽然对于苹果来说，这看上去只是每年一次的例行升级，不过结合微软在7月底的大动作，今年的桌面操作系统大战，很有可能是这两家巨头厂商对于抢夺用户...
Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
...
EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
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