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Correct way to write line to file?
...le:
the_file.write('Hello\n')
From The Documentation:
Do not use os.linesep as a line terminator when writing files opened in text mode (the default); use a single '\n' instead, on all platforms.
Some useful reading:
The with statement
open()
'a' is for append, or use
'w' to write wi...
How do I change the working directory in Python?
...
You can change the working directory with:
import os
os.chdir(path)
There are two best practices to follow when using this method:
Catch the exception (WindowsError, OSError) on invalid path. If the exception is thrown, do not perform any recursive operations, especial...
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...
Deleting folders in python recursively
...o. As asked, the question was how to delete EMPTY directories.The docs for os.walk give an example that almost exactly matches this question: import os for root, dirs, files in os.walk(top, topdown=False): for name in dirs: os.rmdir(os.path.join(root, name))
...
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
...
sed: print only matching group
...it with a 2nd grep.
# To extract \1 from /xx([0-9]+)yy/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'xx[0-9]+yy' | grep -Eo '[0-9]+'
123
4
# To extract \1 from /a([0-9]+)b/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'a[0-9]+b' | grep -Eo '[0-9]+'
678
9
...
How do I execute a program from Python? os.system fails due to spaces in path
...
Yes, the os.exec* functions will replace the current process, so your python process won't continue. They're used more on unix where the general method for a shell to launch a command is to fork() and then exec() in the child.
...
How to write log to file
...
os.Open() must have worked differently in the past, but this works for me:
f, err := os.OpenFile("testlogfile", os.O_RDWR | os.O_CREATE | os.O_APPEND, 0666)
if err != nil {
log.Fatalf("error opening file: %v", err)
}
def...
How to create new folder? [duplicate]
...uld create a new folder with folder name as given in the program. Is this possible? If yes, please let me know how.
3 Answe...
Reading and writing environment variables in Python? [duplicate]
...
Try using the os module.
import os
os.environ['DEBUSSY'] = '1'
os.environ['FSDB'] = '1'
# Open child processes via os.system(), popen() or fork() and execv()
someVariable = int(os.environ['DEBUSSY'])
See the Python docs on os.environ...