Programming_Tips/python.md

PYTHON

Get variable name as a string:

blah = 1
blah_name = [ k for k , v in locals (). iteritems () if v is blah ][ 0 ]

WARNING : Not very clever however, as variables in Python may have more that one name ! Use with caution!

Replace a part of a table [Numpy]:

small_BW=where((L[temp[ptr-1]]==ptr),1,0)
a=BW[posi_0:posi_1,posi_2:posi_3]
a[:,:]=small_BW.copy()

Reshape table without size information:

Put -1 as second argument, the info will automatically be processed.

array.reshape(3,-1)

Concatenate 2 tables [Numpy]:

c=numpy.concatenate((a,b),axis=0)

Cast data in table to int:

Ndarray.astype(int)

Write in the end of a file :

Use add mode :

file.open(file_name, 'a')

Test if variable exists:

try:
    print variable
except NameError:
    print "Error!"

Check if variable is one of several choices:

if a in [b, c,d]:
    blabla

Multi instanciation in Python:

a = b = c = 1+1

WARNING: Those three variables are the same object!

Print function name :

import sys

def tutut():
    """
    Dum function displaying its name!
    """
    print sys._getframe().f_code.co_name

if __name__ == '__main__':
    tutut()

And here is the result

$ python tutut.py
tutut