Python小白--------基础练习题（列表，元组，字典）

今天总结了这几天所学的基础知识，做了一些练习题，都是一些常用操作：

#1：请用代码实现：利用下划线将列表的每一个元素拼接成字符串
# li = ["alex","eric","rain"]
# '_'.join(li)
#2: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'}
# for index,i in enumerate(li):
#     i = i.strip()
#     li[index] = i
#     if i.endswith('c') and (i.startswith('a') or i.startswith('A')):
#         print(i)
# print(li)
# print("------------------------------------")
#
# for i in tu:
#     i = i.strip()
#     if i.endswith('c') and (i.startswith('a') or i.startswith('A')):
#         print(i)
# print(tu)
# print("------------------------------------")
#
# for index,i in enumerate(dic):
#     dic[i] = dic[i].strip()
#     if dic[i].endswith('c') and (dic[i].startswith('a') or dic[i].startswith('A')):
#         print(i)
# print(dic)
# print("------------------------------------")

#3：有如下列表，按照要求实现每一个功能
# li = ['alex','eric','rain']
#   #计算列表长度并输出
# print(len(li))
#   #列表中追加一个元素，并输出添加后的列表
# li.append('brues')
# print(li)
#   #在指定位置插入元素
# li.insert(1,"blues")
#   #修改指定元素
# li[2] = 'Kelly'
#   #删除指定元素
# del li[1]
# del li[2:4]
# print(li)
#   #将列表的所有元素反转
# li.reverse()
# print(li)
#   #输出索引及元素
# for index,i in enumerate(li):
#     print(index,i)

#4:有如下列表，按照需求实现功能
# li = ['hello','secen',['non',['h','kelly'],'all'],123,446]
#    #请根据索引输出指定的元素
# print(li[2][1][1])
#    #找到指定元素并且修改
# li[2][2] = 'ALL'

#5；有如下元组，请按照要求实现指定功能
# tu = ('alex','eric','rain')
#    #计算长度
# print(len(tu))
#    #获取指定元素
# print(tu[1:2])
#    #输出
# for index,i in enumerate(tu):
#     print(index,i)

#6:字典
# dic = {'k1':'v1','k2':'v2','k3':'v3','k4':'v4','k5':[123,4234,24]}
#   #输出所有的key和value
# for i in dic.keys():
#     print(i,end=' ')
#     print(dic[i])
#   #追加
# dic['k6'] = 'v6'
# print(dic)
# dic['k5'].append(44)
# dic['k5'].insert(1,18)
# print(dic)

#7:转换
#    #将字符串转换为列表
# s = 'alex'
# s = list(s)
# print(s)
# print(tuple(s))
#    #将列表转换为元组
# li = ['alex','seven']
# print(tuple(li))
#    #将列表转换为字典
# new_dict = {}
# for index,i in enumerate(li):
#     new_dict[index] = i
#     print(new_dict)
#8:按要求创建字典
# li = [11,22,33,44,55,66,77,88,99]
# new_dict = {'k1':[],'k2':[]}
# for index,i in enumerate(li):
#     if i >=66:
#         new_dict['k1'].append(i)
#     else:
#         new_dict['k2'].append(i)
# print(new_dict)
#9:乘法表
# for i in range(1,10):
#     for j in range(1,i+1):
#         print("%s * %s"%(i,j),end=' ')
#     print('\n')