Is there a way to convert code to string and vice versa in Python?

Question

Original question:

Is there a way to declare macros in Python since they are declared in C:

#define OBJWITHSIZE(_x) (sizeof _x)/(sizeof _x[0])

Here is what I am trying to figure out:

Is there a way to avoid code duplication in Python? In one part of the program that I am writing, I have a function:

def replaceProgramFilesPath(filenameBr):
  def getProgramFilesPath():
    import os
    return os.environ.get("PROGRAMFILES") + chr(92)
  return filenameBr.replace("<ProgramFilesPath>",getProgramFilesPath() )

In another part, I have this code embedded in a line that will later be output to a python file that will be launched by itself:

"""
def replaceProgramFilesPath(filenameBr):
  def getProgramFilesPath():
    import os
    return os.environ.get("PROGRAMFILES") + chr(92)
  return filenameBr.replace("<ProgramFilesPath>",getProgramFilesPath() )
"""

How can I create a “macro” that avoids this duplication?

Answer 1

Answering a new question.

In your first python file (called for example first.py):

import os

def replaceProgramFilesPath(filenameBr):
  new_path = os.environ.get("PROGRAMFILES") + chr(92)
  return filenameBr.replace("<ProgramFilesPath>", new_path)

In the second python file (called for example second.py):

from first import replaceProgramFilesPath
# now replaceProgramFilesPath can be used in this script.

, first.py python , second.py, second.py.

Answer 2

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Answer 3

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. , C, :

import sys
OBJWITHSIZE = lambda x: sys.getsizeof(x) / sys.getsizeof(x[0])
aList = [1, 2, 4, 5]
size = OBJWITHSIZE(aList)
print str(size)

, python, python, - .

- :

import sys
def getSize(x):
   return sys.getsizeof(x) / sys.getsizeof(x[0])

OBJWITHSIZE = getSize
aList = [1, 2, 4, 5]
size = OBJWITHSIZE(aList)
print str(size)

.

, python, :

aList = [1, 2, 4, 5]
size = len(aList)
print str(size)

Answer 4

. Python , #define C.

Answer 5

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Answer 6

, , Metapython:

http://code.google.com/p/metapython/wiki/Tutorial

For instance, the following MetaPython code:

$for i in range(3):
    print $i

will expand to the following Python code:

print 0
print 1
print 2

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Answer 7

"""
from firstFile import replaceProgramFilesPath
"""