print(isfactor) In other words, you are doing a comparison between the object itself rather than invoking the function.

Note though that the is_prime() implementation you provide is not particularly efficient.Īlso, there are might be more efficient ways of achieving this with list comprehension by addressing some corner cases directly, e.g. The reason that your code is returning blank when you run it, is because you are comparing a function type to the value of True, rather than calling it. In that case, the code would read: num = 10 Here is source code of the Python Program to Display All the Prime Numbers Between 1 to 100. To generate a list of the first N prime numbers in Python, you can create your own function and loop until you have N prime numbers. However, if you define a function for primality test (like is_prime()), you can achieve better performances for large numbers. Here prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. In Python, we can create a list of prime numbers easily all we need is a custom function to check if a number is prime or not. If instead you want to obtain the primes in a given range, say below some number num, this can be achieved (more or less efficiently) by: num = 10 If you want to get to a list of the first n with a list comprehension only, I am afraid this is not extremely efficient as there is no straightforward way to get to know how many objects are going to be generated beforehand.

A FOR loop will be used to calculate the Python prime numbers that make the code iterate till the upper limit is reached. From your question it is unclear what the problem is and what kind of tools are you expecting to be used. To find all the prime numbers that lie between an upper and lower limit, such as 1 and 100, these limits will need to be defined.

Prime number list to 100 python