013-python基础-课堂练习
一、练习一
1.1 使用while循环输入 1 2 3 4 5 6 8 9 10
方法一：
1 for i in range(1,11): 2 print(i)
方法二：
1 i = 1 2 while i <= 10: 3 print(i) 4 i += 1
1.2 求1-100的所有数的和
1 i = 1 2 i_sum = 0 3 while i <= 100: 4 i_sum = i + i_sum 5 i += 1 6 print(i_sum)
1.3 输出 1-100 内的所有奇数
1 i = 1 2 while i <= 100: 3 mod = i % 2 # "%"用于求余数 4 if mod == 1: print(i) 5 i += 1
1.4 输出 1-100 内的所有偶数
1 i = 1 2 while i <= 100: 3 mod = i % 2 # "%"用于求余数 4 if mod == 0: print(i) 5 i += 1
1.5 求1-2+3-4+5 ... 99的所有数的和
方法一：
1 i = 1 2 m = 0 3 while i <= 100: 4 mod = i % 2 5 if mod == 0: 6 z = -i 7 else: 8 z = i 9 m = m + z 10 i += 1 11 print(m)
方法二：
1 i = 1 2 m = 0 3 flag = True 4 while i <= 100: 5 if flag is True: 6 m = m + i 7 flag = False 8 else: 9 m = m - i 10 flag = True 11 i += 1 12 print(m)
二、练习二
2.1、元素分类
有如下值集合 [11,22,33,44,55,66,77,88,99,90...]，将所有大于 66 的值保存至字典的第一个key中，将小于 66 的值保存至第二个key的值中。
即： {'k1': 大于66的所有值, 'k2': 小于66的所有值}
方法一：
1 ll = [11,22,33,44,55,66,77,88,99,] 2 dict = {"k1":[],"k2":[]} 3 for i in ll: 4 if i > 66: 5 dict["k1"].append(i) 6 else: 7 dict["k2"].append(i) 8 print(dict)
方法二：
1 ll = [11,22,33,44,55,66,77,88,99,] 2 a = [] 3 b = [] 4 5 for i in ll: 6 if i >= 66: 7 a.append(i) 8 else: 9 b.append(i) 10 c = {"key1":a,"key2":b} 11 print(c)
2.2、查找
查找列表中元素，移除每个元素的空格，并查找以 a或A开头 并且以 c 结尾的所有元素。
li = ["alec", " aric", "Alex", "Tony", "rain"]
tu = ("alec", " aric", "Alex", "Tony", "rain")
dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"}
1 li = ["alec", " aric", "Alex", "Tony", "rain"] 2 for i in li: 3 b = i.strip() 4 if b.startswith("a") or b.startswith("A") and b.endswith("c"): 5 print(b)
1 tu = ("alec", " aric", "Alex", "Tony", "rain") 2 for i in tu: 3 b = i.strip() 4 if b.startswith("a") or b.startswith("A") and b.endswith("c"): 5 print(b)
1 dic = {'k1': "alex", 'k2': ' aric', "k3": "Alex", "k4": "Tony"} 2 for key in dic: 3 b = dic[key].strip() 4 if b.startswith("a") or b.startswith("A") and b.endswith("c"): 5 print(b)
