Start your data science journey with Python. Learn practical Python programming skills for basic data manipulation and analysis.

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- Python Essentials for Data Analysis II
- 2.1 Introduction to Functions in Python
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- 2.4 Functions - A Fun Exercise!
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- PD.1 Introduction to Pandas
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- Data Analysis with NumPyToggle Dropdown
- NP.1 Introduction to NumPy
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- NP.4 Array Slicing
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- NP.6 Math with NumPy I
- NP.7 Combining 2 arrays
- NP.8 Adding elements to arrays
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- NP.11 Finding unique elements and sorting
- NP.12 Math with NumPy II
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Let's create a function that will help us check if a number is prime.

A number is prime if the number is only divisible by 1 and itself.

This function will take in 1 argument, N, which is the number we want to check. Next, it will go through all the numbers from 1 to N and perform modulo checks.

1. In your function, you can use a for-loop together with if-else conditions

2. Make use of `%`

in python to find out the remainder. To find the remainder of 3 divided by 2, we write `3%2`

3. Take the given number and find the remainder when divided by all numbers from 1 to itself. Check whether the conditions for a prime number is met.

4. When a given number is divisible by another number, it is not prime. Use `break`

to stop a for-loop without returning anything

Take note on how the `else` lines up under `for`

instead of `if`

. We want the `for`

loop to check all numbers 2 to N-1 before confirming that our number is prime. Should the `else`

be alligned with `if`

inside the `for`

loop, we will be printing "is prime" before exhausting all possibilities.

`break`

was introduced because once we have discovered that the number is not prime (i.e can be divided by a number that is not 1 and itself) we can stop checking and break out of the `for`

loop.

- Last Updated: Feb 6, 2024 10:02 AM
- URL: https://libguides.ntu.edu.sg/python
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