check prime

Author: qiwsir

newcodes/answers/q44.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# coding=utf-8
+
+import math  
+
+def isPrime1(n):
+    if n <= 1:  
+        return False 
+    for i in range(2, int(math.sqrt(n)) + 1):  
+        if n % i == 0:  
+            return False
+    return True
+
+def isPrime2(n):
+    if n <= 1:
+        return False
+    i = 2
+    while i*i <= n:
+        if n % i == 0:
+            return False
+        i += 1
+    return True
+
+from itertools import count
+
+def isPrime3(n):
+    if n <= 1:
+        return False
+    for i in count(2):
+        if i * i > n:
+            return True
+        if n % i == 0:
+            return False
+
+def isPrime4(n):
+    if n <= 1:
+        return False
+    if n == 2:
+        return True
+    if n % 2 == 0:
+        return False
+    i = 3
+    while i * i <= n:
+        if n % i == 0:
+            return False
+        i += 2
+    return True
+
+if __name__ == "__main__":
+    p = []
+    for i in range(1, 10):
+        if isPrime4(i):
+            p.append(i)
+    print(p)