python3+入门小知识整理，直接拷贝运行即可

 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 = 0
while (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,\n
world''')

age = 1
while (age<10):
    if (age>5):
        print("now nums=%s" % age)
        break
        pass
    else:
      print(r'---nums=%s' % age)
      age+=1


test_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))