Question
In Python you are familiar with importing the os module and using different exec variations. What are some reasons that you would not use os.execlp?

Answer
1. If you use os.execlp to call another program, that program is more likely to return “Killed”. The resources of the child process are, by default, more limited in part because the fork operation is expensive from a system’s resources perspective.

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Continue reading “In Python, What Are Some Disadvantages to Using os.execlp to Fork a Process?”

Problem scenario
You want to check the runtime duration of a section of Python code. How do you compute the amount of time something took in Python?

Solution
Write a program like this:

import datetime, time
t1 = datetime.datetime.now()
time.sleep(5) # replace this line with the section of code you want to time
t2 = datetime.datetime.now()
t3 = t2 – t1
print(“Time format is in hours:minutes:seconds:seconds_decimals”)
print(t3) …

Continue reading “How Do You Get Python to Compute How Long Something Took?”

Problem scenario
You want to write a program to call a bound function in a new thread. How do you do this?

Solution
Run this program (e.g., python foobar.py):

import _thread as thread
class mighty:
def cool():
print(“Cool.”)
def contint():
print(“Hello!”)
if name == “main”:
foobar = thread.start_new_thread(mighty.cool, () )
print(“thread finished…exiting”)

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Continue reading “In Python, How Do You Call a Bound Function as a New Thread with the thread Module?”

Problem scenario
(The old problem scenario was “You want to write a program to call a unbound function in a new thread with the threading module. How do you do this?”)

You want to write a program to call a function in a new thread with the threading module. How do you do this?

Solution
Run this program (e.g.,

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Continue reading “In Python, How Do You Call a Function as a New Thread with the threading Module?”

Problem scenario
You want to create new processes with the multiprocessing library in Python. What should you do?

Solution
Run this program:

“”” In a duplicate terminal window, run this command before, during and after you run the pyhon script: sudo ps -ef | grep python | wc -l

The integer that returns will go up by two showing a new processes have been created when the program is still running. …

Continue reading “How Do You Write a Python Program to Create New Processes with the multiprocessing Library?”

Problem scenario
You want to know how dictionaries perform as iterables in Python. In Python for printing the values of every key-value pair in a dictionary, is it faster or slower than printing every item in a list? How does it compare to a tuple?

Solution
For this example we use integer keys in the dictionary. Keys can be strings or other objects.

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Continue reading “In Python Are Dictionaries Much Slower in Performance Compared to Lists or Tuples?”