python入门练习题

1、第一题是，给出由5、6、7、8组成的数字不重复的所有的三位数：for i in range(5,9): for j in range(5,9): for k in range(5,9): if( i != k ) and (i != j) and (j != k): print(100*i+10*j+k)

3、输出一个图形阵列：a = 176b = 219print( chr(b),chr(a),chr(a),chr(a),chr(b))print(chr(a),chr(b),chr(a),chr(b),chr(a))print(chr(a),chr(a),chr(b),chr(a),chr(a))print(chr(a),chr(b),chr(a),chr(b),chr(a))print(chr(b),chr(a),chr(a),chr(a),chr(b))

5、10^6以内有多少个素数？h = 0leap = 1;from math import sqrt;from sys import stdout;for m in range(1,1000000): k = int(sqrt(m + 1)); for i in range(2,k + 1): if m % i == 0: leap = 0; break if leap == 1 h += 1; if h % 10 == 0: print('.'); leap = 1;print ('The total is %d' % h);答案是：78499。