How do I get time of a Python program's execution?

Trying your hand at timing

If you need increased precision for your measurements, switch to time.perf_counter(). It provides a high-resolution timer which is more suitable for timing small sections of code. To present the time duration in a more user-friendly format, use the datetime.timedelta function:

import time
from datetime import timedelta

start = time.perf_counter()
# Right here, this is where all the magic happens
end = time.perf_counter()

duration = timedelta(seconds=end-start)
print(f'Execution Time: {duration}')
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Quick and Dirty Command Line Timing

For those who love the terminal, whip up a quick execution time using time on the command line:

$ time python your-script.py
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This would give you a rough idea of the execution time. Spice it up with -v(verbose mode) to get detailed juice on execution:

$ time -v python your-script.py
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These would give you insights into memory usage, context switches, I/O stats, among other things.

Precision and Performance

Choose the right tool for the job

Depending on the specificity of your task, you'll need to select an appropriate timer:

• time.time() for simple, non-critical timings
• time.process_time() when you care about CPU time
• time.perf_counter() for high-precision wall-clock measurements
• time.monotonic() to avoid hiccups due to system clock updates

In-depth Code Profiling

For an in-depth understanding of where exactly your code is spending most of its time, you can go nuclear with Python's built-in cProfile module:

import cProfile

cProfile.run('your_mystery_function()')
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This will output a detailed performance report of your function, basically the blueprint of your code's runtime behavior.

System-Level Performance

To monitor system-level performance, memory usage and context switches, the secret might lie outside Python; more precisely, in Linux's /usr/bin/time:

/usr/bin/time -v python your-script-here.py
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Verbose mode will provide insights into memory consumption and process scheduling, keys to the elusive land of optimized code.