How do you print a prime number in python?
A positive integer greater than 1 which has no other factors except 1 and the number itself is called a prime number. Show 2, 3, 5, 7 etc. are prime numbers as they do not have any other factors. But 6 is not prime (it is composite) since, Source Code
Output Prime numbers between 900 and 1000 are: 907 911 919 929 937 941 947 953 967 971 977 983 991 997 Here, we store the interval as lower for lower interval and upper for upper interval, and find prime numbers in that range. Visit this page to learn how to check whether a number is prime or not. Example to check whether an integer is a prime number or not using for loop and if...else statement. If the number is not prime, it's explained in output why it is not a prime number. To understand this example, you should have the knowledge of the following Python programming topics:
A positive integer greater than 1 which has no other factors except 1 and the number itself is called a prime number. 2, 3, 5,
7 etc. are prime numbers as they do not have any other factors. But 6 is not prime (it is composite) since, Example 1: Using a flag variable
In this program, we have checked if num is prime or not. Numbers less than or equal to 1 are not prime numbers. Hence, we only proceed if the num is greater than 1. We check if num is exactly divisible by any number from Outside the loop, we check if
Note: We can improve our program by decreasing the range of numbers where we look for factors. In the above program, our search range is from 2 to We could have used the
range, You can change the value of variable num in the above source code to check whether a number is prime or not for other integers. In Python, we can also use the Example 2: Using a for...else statement
Output 407 is not a prime number 11 times 37 is 407 Here, we have used a It works on the logic that the So, in the Here's a simple and intuitive version of checking whether it's a prime in a RECURSIVE function! :) (I did it as a homework assignment for an MIT class) In python it runs very fast until 1900. IF you try more than 1900, you'll get an interesting error :) (Would u like to check how many numbers your computer can manage?)
Of course... if you like recursive functions, this small code can be upgraded with a dictionary to seriously increase its performance, and avoid that funny error. Here's a simple Level 1 upgrade with a MEMORY integration:
Here are the resuls, where I printed the last 100 prime numbers found.
There are 9594 prime numbers, until 100000 [99991, 99989, 99971, 99961, 99929, 99923, 99907, 99901, 99881, 99877, 99871, 99859, 99839, 99833, 99829, 99823, 99817, 99809, 99793, 99787, 99767, 99761, 99733, 99721, 99719, 99713, 99709, 99707, 99689, 99679, 99667, 99661, 99643, 99623, 99611, 99607, 99581, 99577, 99571, 99563, 99559, 99551, 99529, 99527, 99523, 99497, 99487, 99469, 99439, 99431, 99409, 99401, 99397, 99391, 99377, 99371, 99367, 99349, 99347, 99317, 99289, 99277, 99259, 99257, 99251, 99241, 99233, 99223, 99191, 99181, 99173, 99149, 99139, 99137, 99133, 99131, 99119, 99109, 99103, 99089, 99083, 99079, 99053, 99041, 99023, 99017, 99013, 98999, 98993, 98981, 98963, 98953, 98947, 98939, 98929, 98927, 98911, 98909, 98899, 98897] ... It took your computer 0:00:40.871083 to calculate it So It took 40 seconds for my i7 laptop to calculate it. :) How do I print a prime number?First, take the number N as input. Then use a for loop to iterate the numbers from 1 to N. Then check for each number to be a prime number. If it is a prime number, print it.
How do you print prime numbers from 1 to 100 in Python?num1 = input("Input a number: ") num2 = input("Input another number: ") for x in range(num1,num2): prime = True for i in range(2,x): if (x%i==0): prime = False if prime == True: print x print "Done......" It classifies 1 as a Prime Number, which is incorrect.
Is there a prime number function in Python?Python Function to Check for Prime Number
The above function is_prime() takes in a positive integer n as the argument. If you find a factor in the specified range of (2, n-1), the function returns False —as the number is not prime. And it returns True if you traverse the entire loop without finding a factor.
How do you print prime and composite numbers in Python?Approach :. Read input number using input() or raw_input() .. Check if num is greater than 1.. Find factors. Run a for loop ranging from 2 to the num entered. ... . If the number entered is either 0 or 1, we say that the number is neither prime nor composite number.. All other numbers are composite numbers.. Print the result.. |