标签：sdi dig with 小练习 move pytho 类型 并且 切分
msg = 'hello world'
print(f'msg[6]: {msg[6]}')
print(f'msg[-3]: {msg[-3]}')msg[6]: w
msg[-3]: r
msg = 'hello nick'
print(f'msg[3:]: {msg[3:]}')
print(f'msg[3:8]: {msg[3:8]}')
print(f'msg[3:8:2]): {msg[3:8:2]}')
print(f'msg[3::2]: {msg[3::2]}')
print(f'切片所有：{msg[:]}')
print(f'反转所有 msg[::-1]: {msg[::-1]}')
print(f'切片-5~-2: {msg[-5:-2:1]}')
print(f'切片-2~-5: {msg[-2:-5:-1]}')
msg[3:]: lo nick msg[3:8]: lo ni msg[3:8:2]): l i msg[3::2]: l ik 切片所有：hello nick 反转所有 msg[::-1]: kcin olleh 切片-5~-2: ni 切片-2~-5: cin
msg = 'hello nick'
print(len(msg))10
msg = 'my name is micheal, micheal is handsome'
print(f"'nick' in msg: {'nick' in msg}")
print(f"'jason' not in msg: {'jason' not in msg}")
print(f"not 'jason' in msg: {not 'jason' in msg}") ‘nick‘ in msg: False ‘jason‘ not in msg: True not ‘jason‘ in msg: True
name = '&&&n ick'
print(f"name.strip('&'): {name.strip('&')}") #strip()默认为' ', 并且不修改原值，新创建空间
print(f'name: {name}')
#strip()应用场景
pwd = input('password: ') #用户可能会手抖输入空格
if pwd.strip() == '123':
print('密码输入成功')
print(f"'*-& nick'.strip('*-& nick'): {'*-& nick'.strip('*-& ')}")
name.strip(‘&‘): n ick name: &&&n ick password: 123 密码输入成功 ‘*-& nick‘.strip(‘*-& nick‘): nick
info = "nick:male:19"
info_list1 = info.split(':')
info_list2 = info.split(':', 1)
print(f'info_list1:{info_list1}')
print(f'info_list2:{info_list2}')info_list1:[‘nick‘, ‘male‘, ‘19‘] info_list2:[‘nick‘, ‘male:19‘]
msg = 'hello nick'
for i in msg:
print(i,end=' ')h e l l o n i c k
name = 'Nick Chen'
print(f"name.upper(): {name.upper()}")
print(f"name.lower(): {name.lower()}")name.upper(): NICK CHEN name.lower(): nick chen
name = 'Nick Chen'
print(f"name.startswith('Nick'): {name.startswith('Nick')}")
print(f'name.endswith('chen'): {name.endswith('chen')}')name.startswith(‘Nick‘): True name.endswith(‘chen‘): False
#str值replace()
name = 'nick shuai'
print(f"name.replace('shuai', 'handsome'): {name.replace('shuai', 'handsome')}")name.replace(‘shuai‘, ‘handsome‘): nick handsome
lis = [1, 3, '13']
print(f"':'.join(lis): {':'.join(lis)}") #报错，数字不可和字符串拼接
#str值join（）
lis = ['nick', 'male', '19']
print(f"':'.join(lis): {':'.join(lis)}")‘:‘.join(lis): nick:male:19
#str之isdigit()应用场景
age = input('age: ')
if age.isdigit():
age = int(age)
if age < 18:
print('小姐姐好')
else:
print('阿姨好’)
else:
print(f'你的年龄能是这个{age}？')age: 12 小姐姐好
# list之追加值
name_list = ['nick', 'jason', 'tank', 'sean']
name_list.append('tank sb')
print(f"name_list: {name_list}")
name_list: [‘nick‘, ‘jason‘, ‘tank‘, ‘sean‘, ‘tank sb‘]
list之删除
name_list = ['nick', 'jason', 'tank', 'sean']
del name_list[2]
print(f"name_list: {name_list}")name_list: [‘nick‘, ‘jason‘, ‘sean‘]
#list之insert
name_list = ['nick', 'jason', 'tank', 'sean']
name_list.insert(1, 'handsome')
print(f'name_list: {name_list}')name_list: [‘nick‘, ‘handsome‘, ‘jason‘, ‘tank‘, ‘sean‘]
#list之pop(),pop()默认删除最后一个元素
name_list = ['nick', 'jason', 'tank', 'sean']
print(f'name_list.pop(1): {name_list.pop(1)}')name_list.pop(1): jason
# list之remove()
name_list = {'nick', 'jason', 'tank', 'sean'}
print(f'name_list.remove("nick"): {name_list.remove("nick")}')name_list.remove("nick"): None#list之count()
name_liat = ['nick', 'jason', 'tank', 'sean']
print(f"name_list.count('nick'): {name_list.count('nick')}")
name_list.count(‘nick‘): 1
#list之index()
name_list = ['nick', 'jason', 'tank', 'sean']
print(f"name_list.index('nick'): {name_list.index('nick')}")name_list.index(‘nick‘): 0
#list之extend
name_list = ['nick', 'jason', 'tank', 'sean']
name_list2 = ['nick handsome']
name_list.extend(name_list2)
print(f"name_list: {name_list}")name_list: [‘nick‘, ‘jason‘, ‘tank‘, ‘sean‘, ‘nick handsome‘]
#list之reverse()
name_list = ['nick', 'jason', 'tank', 'sean']
name_list.reverse()
print(f"name_list: {name_list}")name_list: [‘sean‘, ‘tank‘, ‘jason‘, ‘nick‘]
#list之sort(), 使用sort列表的元素必须是同类型的
name_list = ['nick', 'jason', 'tank', 'sean']
name_list.sort()
print(f"name_list: {name_list}")
name_list.sort(reverse = True)
print(f"name_list_reverse: {name_list}")name_list: [‘jason‘, ‘nick‘, ‘sean‘, ‘tank‘] name_list_reverse: [‘tank‘, ‘sean‘, ‘nick‘, ‘jason‘]
#dict之按key取值
dic = {'a': 1, 'b': 2}
print(f"first dic['a']: {dic['a']}")
dic['a'] = 3 #可以对原值进行修改
print(f"second dic['a']: {dic['a']}")
first dic[‘a‘]: 1 second dic[‘a‘]: 3
# dic之删除del
dic = {'a': 1, 'b': 2}
del dic['a']
print(f"dic.get('a'): {dic.get('a')}")
# dic之删除pop
dic = {'a': 1, 'b': 2}
dic.pop('a') #指定元素删除
print(f"dic.pop('a'):{dic.pop('a')}")
print(f"dic.pop('b'):{dic.pop('b')}")dic.get(‘a‘): None
dic.get(‘a‘): None
dic.pop(‘b‘): 2
dic = {'a': 1, 'b': 2}
print(f"dic.items(): {dic.items()}")dic = {‘a‘: 1, ‘b‘: 2}print(f"dic.items(): {dic.items()}")
# dic之循环
# dic是无序的，但是python3采用了底层优化算法，所以看起来是有序的，但是python2中的字典是无序
dic = {'a': 1, 'b': 2, 'c': 3, 'd': 4}
for k, v in dic.items():# items可以换成keys()、values()
print(k, v,end=' ')
dic = {‘a‘: 1, ‘b‘: 2, ‘c‘: 3, ‘d‘: 4}for k, v in dic.items():# items可以换成keys()、values() print(k, v,end=‘ ‘)
# dic之get()
dic = {'a': 1, 'b': 2}
print(f"dic.get('a'): {dic.get('a')}")
print(f"dic.get('c'): {dic.get('c')}")dic.get(‘a‘): 1
dic.get(‘c‘): None
# dic之update()
dic1 = {'a': 1, 'b': 2}
dic2 = {'c': 3}
dic1.update(dic2)
print(f"dic1: {dic1}")dic1: {‘a‘: 1, ‘b‘: 2, ‘c‘: 3}
#dic之setdefault() 有指定key不会改变值，无指定key则改变值
dic = {'a': 1, 'b': 2}
print(f"dic.setdefault('a'): {dic.setdefault('a',3)}")
print(f"dic: {dic}")
print(f"dic.setdefault('c'): {dic.serdefault('c',3)}")
print(f"dic: {dic}")dic.setdefault(‘a‘): 1
dic: {‘a‘: 1, ‘b‘: 2}
dic.setdefault(‘c‘): 3
dic: {‘a‘: 1, ‘b‘: 2, ‘c‘: 3}
统计s = ‘hello tank tank say hello sb sb’中每个单词的个数
s = 'hello tank tank say hello sb sb'
s_split = s.split()
dic = dict()
for i in s:
if i in dic:
dic[i] += 1
else:
dic[i] = 1
print(dic){‘hello‘: 2, ‘tank‘: 2, ‘say‘: 1, ‘sb‘: 2}
标签：sdi dig with 小练习 move pytho 类型 并且 切分
原文地址：https://www.cnblogs.com/michealjy/p/11311190.html
