• SiaProgrammingPythonDatatypes

Variable names

Allowed names for identifier (name of variable or function):

• Any sequence of alphabetical character, number, or underline character _

• First symbol has to be a character
• Case sensitive
• Not a python built-in keyword

Name space

The Python interpreter maps the name of an identifier in the active name space. The active name space depends on the active code block (module, function). The identifier can be local or global with respect to the active code block.

   1 def bad_style(x):
   2         # Name space of bad_style
   3         global y
   4         y=x 
   5         z=x
   6         return x
   7 
   8 # Name space of __main__
   9 x,y,z=2,2,2
  10 x=bad_style(1)
  11 print 'x=',x,'y=',y,'z=',z
  12 # y is changed!

   1 import scipy
   2 scipy.pi # pi is in the name space of scipy
   3 
   4 from scipy import pi
   5 pi # pi is in the active name space
   6 
   7 from scipy import *
   8 pi # all identifiers of scipy are in the active name space
   9 
  10 del(pi) # Deletes pi from the active name space
  11 reset   # ipython function to delete all identifiers

Built-in

Scalar

• Plain integer: 9

• Long integer: 9**99, 1L

• Hex integer: 0x10

• Floating point: 0.1

• Exponential floating point: 1e-3

• Complex: 3+2j

Casting

• int()
• long()
• float()
• complex()
• str()

Sequences

String

Tuple

List

Dictionary

Extended data types

Array

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