start_example.py

import os, sys

"""
Script to execute example-files from outside the pygvisuals-package
"""

def has_main_loop(f):
    """
    Simple test to see if a py-file has a method called 'main_loop'
    """
    if not f.lower().endswith(".py"):
        return False
    
    try:
        descriptor = open(f)
    except:
        return False
    try:
        while True:
            try:
                line = descriptor.readline()
            except:
                line = None
            if not line:
                break
            if line.startswith("def main_loop():"):
                descriptor.close()
                return True
        descriptor.close()
        return False
    except:
        descriptor.close()
        return False

### Scan Directory ###

examples = []

for root, dirs, files in os.walk(os.path.join("pygvisuals", "examples")):
    for f in files:
        if has_main_loop(os.path.join(root, f)):
                 examples.append(os.path.join(root, f))

print "List of executable examples:"
for e in range(len(examples)):
    print str(e) + ":", examples[e]

### Handle User-Input ###

print ""
print "Choose an example to execute with its index! (type 'exit' to exit)"

index = None
while index == None:
    userinput = raw_input("index: ")
    if userinput.lower() == "exit":
        sys.exit()
        break
    try:
        index = int(userinput)
        if index >= len(examples) or index < 0:
            print "Could not find example of index", index
            index = None
    except:
        print "Invalid index!"
        index = None
print "Executing:", examples[index]
__import__(examples[index].replace(os.sep, "."))