# Python Exercise: Invoke a given function after specific milliseconds

## Python Functions: Exercise - 21 with Solution

Write a Python program that invokes a function after a specified period of time.

**Sample Solution**:

**Python Code:**

```
# Import specific functions 'sleep' from the 'time' module and the 'math' module
from time import sleep
import math
# Define a function named 'delay' that delays the execution of a function by the given milliseconds
def delay(fn, ms, *args):
# Sleep for the specified number of milliseconds
sleep(ms / 1000)
# Call the provided function 'fn' with the given arguments '*args' and return the result
return fn(*args)
# Print a message indicating the operation that follows
print("Square root after specific milliseconds:")
# Call the 'delay' function with a lambda function to calculate square roots after specific delays
# Print the square root of 16 after a delay of 100 milliseconds
print(delay(lambda x: math.sqrt(x), 100, 16))
# Print the square root of 100 after a delay of 1000 milliseconds
print(delay(lambda x: math.sqrt(x), 1000, 100))
# Print the square root of 25100 after a delay of 2000 milliseconds
print(delay(lambda x: math.sqrt(x), 2000, 25100))
```

Sample Output:

Square root after specific miliseconds: 4.0 10.0 158.42979517754858

**Explanation:**

In the exercise above the code demonstrates the usage of the "delay()" function, which delays the execution of a provided function ('fn') by a specified number of milliseconds ('ms'). It imports the necessary modules, defines the "delay()" function, and then applies the "delay()" function to calculate square roots after specific delays, using lambda functions with different arguments and delays provided in milliseconds.

**Flowchart: **

**Python Code Editor:**

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