"Python"의 두 판 사이의 차이

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==File existence==
 
==File existence==
import os.path
 
 
  os.path.exists(file_path)
 
  os.path.exists(file_path)
 
[http://stackoverflow.com/a/82846/766330] [https://docs.python.org/2/library/os.path.html#os.path.exists]
 
[http://stackoverflow.com/a/82846/766330] [https://docs.python.org/2/library/os.path.html#os.path.exists]

2017년 4월 10일 (월) 12:07 판

Time

>>> import time
>>> time.time()
1491792653.410371
>>> import datetime
>>> datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')
'2017-04-10 11:51:17'  
>>> datetime.datetime.utcnow()
datetime.datetime(2017, 4, 10, 2, 51, 34, 356682)
>>> datetime.datetime.now()
datetime.datetime(2017, 4, 10, 11, 51, 36, 572681)
>>> datetime.datetime.now().strftime("%A, %d. %B %Y %I:%M%p")
'Monday, 10. April 2017 11:51AM'

[1]


is and ==

is is identity testing, == is equality testing. what happens in your code would be emulated in the interpreter like this:

>>> a = 'pub'
>>> b = ''.join(['p', 'u', 'b'])
>>> a == b
True
>>> a is b
False

[2]


Access index in for loop

for idx, val in enumerate(ints):
   print(idx, val)

[3]


Max integer

sys.maxint

[4]


Argument parsing

use argparse


range by step

>>> step = .1
>>> N = 10     # number of data points
>>> [ x / pow(step, -1) for x in range(0, N + 1) ]
[0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]

[5]


File existence

os.path.exists(file_path)

[6] [7]


==