# This file explains how a valid ".py" can be processed "as-is" 
#   by Python to produce minimal results . . . or
#   by IX to produce results with entityName substitutions. 
#
# But if an equivalent ".ix" file is the source file, less coding is necessary.
# Note that such a ".py" file needs some specific comments to be processed by IX. 
# Note also that a Python compile error occurs if the first line is not isIX=False
#
# Note that using the &macroIX+ line shown below will always include multiple lines of 
#    macroIX code when processed by IX whose processing will perform the
#    appropriate entityName substitutions:
# 
#&+ &macroIX+=clickableImageA_html.ix?imageNameA="USASCII-8bit.jpg" &+

# by D@CC on 2022FJun22
#
# The following code can be processed by either Python or IX:


isIX = False
#&+ isIX=True &+
#&+ &count+=2 #initial value &+
# program test1_ix.py
# becomes
# program test1.py
if Not isIX : count=1        #this statement is active if isIX = False
#&+ if isIX : count=&count+  #this statement is active if isIX = True &+
for i in range(count):
    print("line",i+1)
#for end

runs as-is under Python using count=1.

under IX with &count+ undefined, the above code is converted to:

isIX=False
isIX=True
count=2 #initial value
# program test1_ix.py
# becomes
# program test1.py
if Not isIX : count=1
if isIX : count=2    #uses initial value because undefined command line &count+
for i in range(count):
    print("line",i+1)
#for end

under IX with &count+ defined in command line as 10 is converted to:

isIX=False
isIX=True
count+=2
# program test1_ix.py
# becomes
# program test1.py
if Not isIX : count=1
if isIX: count=10   #uses count in command line because &count+ is defined 
for i in range(count):
    print("line",i+1)
#for end

##################################################################

but it takes less code (and produces less code) if macro is test1_py.ix, shown immediately below

#&+ isIX=True &+
#&+ &count+=2 #initial value &+
# program test1_py.ix
# becomes
# program test1.py
count=&count+
for i in range(count):
    print("line",i+1)
#for end

under IX with &count+ undefined, the converted result is

# program test1_py.ix
# becomes
# program test1.py
count= 2
for i in range(count):
    print("line",i+1)
#for end

under IX with &count+=10 in command line, the converted result is

# program test1_py.ix
# becomes
# program test1.py
count= 10
for i in range(count):
    print("line",i+1)
#for end

However if the above "test1_py.ix" code is processed by Python, an error will be raised
because "count=&count+" is an invalid Python statement.

#Conclusion
# The first code set is test1_ix.py
# The fourth code set is test1_py.ix
# Submitting the first code set to Python ----
     will print 1 line
# Submitting the first code set (or the fourth code set) to IX with an undefined entityName of count ----
     will print 2 lines because &count+ has an ititial value of 2
# Submitting the first code set (or the fourth code set) to IX with entityName count=10----
     will print 10 lines because &count+ is defined to be 10 on the command line.


#/test1_py_ix_examples.txt