1  #!/usr/bin/env python3
  2  """
  3  Example: Lazy Imports & Fast Startup
  4  
  5  Demonstrates how PraisonAI Agents uses lazy imports to achieve
  6  fast startup times and reduced memory usage.
  7  """
  8  import sys
  9  import time
 10  
 11  
 12  def example_verify_lazy_imports():
 13      """Verify that heavy dependencies are not loaded at import time."""
 14      print("=" * 60)
 15      print("Lazy Imports Verification")
 16      print("=" * 60)
 17      
 18      # Clear any cached imports
 19      heavy_deps = ['litellm', 'chromadb', 'mem0', 'requests']
 20      for dep in heavy_deps:
 21          for key in list(sys.modules.keys()):
 22              if key.startswith(dep):
 23                  del sys.modules[key]
 24      
 25      # Measure import time
 26      start = time.perf_counter()
 27      import praisonaiagents
 28      elapsed = (time.perf_counter() - start) * 1000
 29      
 30      print(f"\nImport time: {elapsed:.1f}ms")
 31      print(f"Target: <200ms")
 32      print(f"Status: {'PASS' if elapsed < 200 else 'FAIL'}")
 33      
 34      # Check lazy imports
 35      print("\nLazy Import Check:")
 36      all_lazy = True
 37      for dep in heavy_deps:
 38          is_lazy = dep not in sys.modules
 39          status = "LAZY (good)" if is_lazy else "EAGER (bad)"
 40          print(f"  {dep}: {status}")
 41          if not is_lazy:
 42              all_lazy = False
 43      
 44      print(f"\nAll lazy: {'PASS' if all_lazy else 'FAIL'}")
 45      return all_lazy
 46  
 47  
 48  def example_measure_memory():
 49      """Measure memory usage after import."""
 50      print("\n" + "=" * 60)
 51      print("Memory Usage Measurement")
 52      print("=" * 60)
 53      
 54      import tracemalloc
 55      
 56      # Clear modules
 57      for key in list(sys.modules.keys()):
 58          if key.startswith('praisonaiagents'):
 59              del sys.modules[key]
 60      
 61      tracemalloc.start()
 62      import praisonaiagents
 63      current, peak = tracemalloc.get_traced_memory()
 64      tracemalloc.stop()
 65      
 66      current_mb = current / 1024 / 1024
 67      peak_mb = peak / 1024 / 1024
 68      
 69      print(f"\nCurrent memory: {current_mb:.1f}MB")
 70      print(f"Peak memory: {peak_mb:.1f}MB")
 71      print(f"Target: <30MB")
 72      print(f"Status: {'PASS' if current_mb < 30 else 'WARN' if current_mb < 45 else 'FAIL'}")
 73      
 74      return current_mb < 45
 75  
 76  
 77  def example_specific_imports():
 78      """Show how to use specific imports for best performance."""
 79      print("\n" + "=" * 60)
 80      print("Specific Imports Example")
 81      print("=" * 60)
 82      
 83      # Good - specific imports are fast
 84      print("\nGood practice - specific imports:")
 85      print("  from praisonaiagents import Agent, Task")
 86      
 87      # Avoid - star imports load everything
 88      print("\nAvoid - star imports load more:")
 89      print("  from praisonaiagents import *")
 90      
 91      # Example of specific import
 92      from praisonaiagents import Agent
 93      print(f"\nAgent class loaded: {Agent.__name__}")
 94  
 95  
 96  if __name__ == "__main__":
 97      print("PraisonAI Agents - Lazy Imports Example")
 98      print("=" * 60)
 99      
100      # Run examples
101      lazy_ok = example_verify_lazy_imports()
102      memory_ok = example_measure_memory()
103      example_specific_imports()
104      
105      print("\n" + "=" * 60)
106      print("Summary")
107      print("=" * 60)
108      print(f"Lazy imports: {'PASS' if lazy_ok else 'FAIL'}")
109      print(f"Memory usage: {'PASS' if memory_ok else 'FAIL'}")
110      print(f"Overall: {'PASS' if lazy_ok and memory_ok else 'FAIL'}")