python3+学习小知识整理，python where循环， python for循环，python 打印参数，python数组求和，python字符串替换等等，后续会持续更新。

#!/usr/bin/env python# -*- coding: utf-8 -*-#where循环count = 0while (count<10):    print ('Th count is', count)    count += 1    print ("down")pass#字符串转移print(arrayList[-1])print('\\\n\\')print(r'\\\r\\') #原样输出print('\n');print('---------------')print('\\\\')print(r'''hello,\nworld''')age = 1while (age<10):    if (age>5):        print("now nums=%s" % age)        break        pass    else:      print(r'---nums=%s' % age)      age+=1test_array = ['kevin','ruby']print(len(test_array))print("len count array is =%s" % len(test_array))#数组末尾追加操作， append函数test_array.append('xxxxxxxxxxxxxx')print("python append array param=%s" % test_array)print(test_array)lists = ['name', 'quest', 'favorite color']print("array list is ：%s" % lists)for i in range(len(lists)):    print("key is =%s" % i , "value is =%s" % lists[i])print("---------------------")#循环判断，条件满足调出循环， range 函数 (开始值，结束之，+值/-值)for k in range(1,100,2):    if k>20:        print("now key is : %s" % k)        break        pass    else:        print("----k===%s" % k)    print("---------------------")string_1 = "abcdefg"#统计字符串长度 len函数，可统计 array，string 等print("now string length is %s" % len(string_1), "nums")#字符串循环单个输出for k in string_1:    print("_%s_" % k)print("字符串获取指定某一位的值===",string_1[5])#从指定位数后面开始替换，保留前面值print("字符替换函数：",string_1[:4]+'___testok!!!') #从指定位数+1开始替换后面，只保留当前位数+1的值print("字符替换函数：",string_1[4]+'___xxxxxxxxxxxx!!!') # 判断是否是整数print(isinstance(111, int))