# Python program to find Prime Numbers between 1 to100.

## Find Prime number between 1 to100

Here, in this page we will discuss program to find Prime number between 1 to100 in python .A prime number is an positive integer that has no divisors  except one and itself or can only be exactly divided by the integers 1 and itself without leaving a remainder.
For example n is prime, if n can only be divided by 1 and n. So prime number has two factor one is 1 another is number itself .

The number 1 is neither prime nor composite.

Example:

• n=7
• divisors of 7 are 1 and 7 itself  so it is a prime number. ## Implementation:

• From 1 to 100 we will start from 2 to check the number of divisors of every number.
• If a number have only two divisors then it is a Prime number. `#To find the prime numbers between 1 to 100 li=[] #list of prime numbers will be stored here for i in range(2,101):    f=0    for j in range(2,i+1):        if(i!=j and i%j==0): #if any n            f=1            break     if(f==0):        li.append(i)print('Prime numbers between 1 to 100:')print(*li,sep=' ')`
`Output:Prime numbers between 1 to 100:2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97`

#### Optimal Solution to find prime number between 1 to 100 :

• This method is known as Sieve of Eratosthenes.
• Time Complexity: O(n*log(logn)) .
• Here n is maximum range.

#### Python Code:

`#To find the prime numbers between 1 to 100 li=[True]*(101)  #list of prime numbers li=False li=Falsep=2 while(p*p<=101):    if(li[p]==True): #if it is a prime number then its multiples will be non-prime        for i in range(p*p,101,p):            li[i]=False     p=p+1print('Prime numbers between 1 to 100:')for i in range(2,101):    if(li[i]==True):        print(i, end=' ')`
`Output:Prime numbers between 1 to 100:2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97`