#==================================================
# 1. Select non-function values:
#==================================================
location = 'myHome'
fileLocation = {'myHome' :path1,
'myOffice' :path2,
'somewhere':path3}[location]
#==================================================
# 2. Select functions:
#==================================================
functionName = input('Enter a function name')
eval('%s()'%functionName)
#==================================================
# 3. Select values with 'range comparisons':
#==================================================
#
# Say, we have a range of values, like: [0,1,2,3]. You want to get a
# specific value when x falls into a specific range:
#
# x<0 : 'return None'
# 0<=x<1: 'return 1'
# 1<=x<2: 'return 2'
# 2<=x<3: 'return 3'
# 3<=x : 'return None'
#
# It is eazy to construct a switch by simply making the above rules
# into a dictionary:
selector={
x<0 : 'return None',
0<=x<1 : 'return 1',
1<=x<2 : 'return 2',
2<=x<3 : 'return 3',
3<=x : 'return None'
}[1]
# During the construction of the selector, any given x will turn the
# selector into a 2-element dictionary:
selector={
0 : 'return None',
1 : #(return something you want),
}[1]
# This is very useful in places where a selection is to be made upon any
# true/false decision. One more example:
selector={
type(x)==str : "it's a str",
type(x)==tuple: "it's a tuple",
type(x)==dict : "it's a dict"
} [1]
#==================================================
# 4. Select functions with 'range comparisons':
#==================================================
#
# You want to execute a specific function when x falls into a specific range:
functionName={
x<0 : setup,
0<=x<1: loadFiles,
1<=x<2: importModules
}[1]
functionName()
#==================================================
# 5. and/or style
#==================================================
#
# x = a and 'a' or None
#
# is same as:
#
# if a: x = 'a'
# else: x = None
#
# More example: a switch in Basic:
#
Select Case x
Case x<0 : y = -1
Case 0<=x<1 : y = 0
Case 1<=x<2 : y = 1
Case 2<=x<3 : y = 2
Case Else : y = 'n/a'
End Select
#
# in Python
#
y = ( (x<0) and -1 ) or \
( (0<=x<1) and 0 ) or \
( (1<=x<2) and 1 ) or \
( (2<=x<3) and 2 ) or 'n/a'
