python语法
- python学习
- 2025-04-02
- 160热度
- 0评论
type
用来检测数据类型
num = 1 print(type(num))
格式化占位符
name = 'fdas' num = 1 print('wds=%s, dfd=%06d' % (name, num))
b = 2.325 print('fsda%.7f' % b)
print("wdw%%fwe%%" %()) wdw%fwe%
name = 'fdfd' age = 324 print(f'名字{name},年龄{age}') 名字fdfd,年龄324
算术运算符
print(1+1) print(6-5) print(6*4) print(6/3)
取整除
print(6//4)
1
幂次方
print(2**5)
32
输入函数
name = input("Enter your name: ") print(name)
转义字符
print('fsdf\tfsdfsd')
print('fsdafd\nfdsaf\n')
print('fsdf\rfds') fds
age = 10 if 0 <= age <= 5: print('1') elif 10<= age <= 18: print('2') else: print('3')
i=1 while i<100: print(i) i=i+1
str = 'fsdafsaf' for i in str: print(i)
for i in range(1,5): #左闭右开 1234 print(i)
str = '你好' str1 = str.encode('utf-8') print(str1) str2 = str1.decode('utf-8') print(str2)
print("ads"+'das') print('fsdaf\n'*3)
name = 'wang' print('n' in name) print('z' in name)
name = "fdsjflsd" print(name[0])
str = 'fsdfasf' #左闭右开 print(str[0:5:2]) fda print(str[3:5]) fa print(str[-1:]) f print(str[-1:-5:-1]) fsaf print(str[:-1]) fsdfas
name = 'abcdefgabcdefg' print(name.find('g')) # 6 print(name.find('cd')) # 2 print(name.find('d',6)) # 10 找不到-1
name = 'abcdefgabcdefg' print(name.index('g')) # 6 print(name.index('cd')) # 2 print(name.index('d',6)) # 10 找不到就报错
name = 'qwerqwer' print(name.count('q')) 2 print(name.count('A')) 0 print(name.count('q',3)) 1
name = 'abcdefg' print(name.capitalize()) # Abcdefg print(name.startswith('a')) # True print(name.endswith('a')) #False print(name.lower()) # abcdefg print(name.upper()) # ABCDEFG
#替换 name = '你好,你们好' print(name.replace('你','他')) # 他好,他们好 print(name.replace('你','他',1)) # 他好,你们好
name = 'a,bc,de,fg' print(name.split(',')) # ['a', 'bc', 'de', 'fg'] print(name.split(',',1)) # ['a', 'bc,de,fg']
#列表 list=[1,2,'sfsd','3.2'] print(list) # [1, 2, 'sfsd', '3.2'] print(list,type(list)) # [1, 2, 'sfsd', '3.2'] <class 'list'> print(list[0]) # 1 print(list[0:3]) # [1, 2, 'sfsd']
for i in list: print(i) # 1 # 2 # sfsd # 3.2
list = ['one','two','three'] list.append('four') print(list) # ['one', 'two', 'three', 'four'] list.insert(0,'five') print(list) # ['five', 'one', 'two', 'three', 'four'] list.extend(['six','seven']) print(list) # ['five', 'one', 'two', 'three', 'four', 'six', 'seven'] list.extend('six') print(list) # ['five', 'one', 'two', 'three', 'four', 'six', 'seven', 's', 'i', 'x']
name = ['li','wang',1] name[2] = 'shi' print(name) # ['li', 'wang', 'shi'] list = ['a','b','c'] print('a' in list) # True
list = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight'] del list[0] print(list) # ['two', 'three', 'four', 'five', 'six', 'seven', 'eight'] list.pop(0) print(list) # ['three', 'four', 'five', 'six', 'seven', 'eight'] list.remove('six') print(list) # ['three', 'four', 'five', 'seven', 'eight']
list = [1,2,3,5,6,8] list.sort() print(list) # [1, 2, 3, 5, 6, 8] list.reverse() print(list) # [8, 6, 5, 3, 2, 1]
list = [] for i in range(1,11): if i % 2 == 0: list.append(i) print(list) # [2, 4, 6, 8, 10] [list.append(i) for i in range(1,11) if i % 2 == 0] print(list) # [2, 4, 6, 8, 10, 2, 4, 6, 8, 10]
list = [1,2,[8,52,5]] print(list[1]) # 2 print(list[2][2]) # 5
元组 tup = (1,2,5,6) print(type(tup)) # <class 'tuple'> print(tup[0]) # 1 print(tup.index(5)) # 2
#字典 dic = {'name':'fsd', 'age':18} print(dic['name']) # fsd print(type(dic)) # <class 'dict'>
dic = {'name':'fsd', 'age':18} print(dic.get('name')) # fsd print(dic.get('number','没有')) # 没有 dic['sex'] = 'male' print(dic) # {'name': 'fsd', 'age': 18, 'sex': 'male'} del dic['name'] print(dic) # {'age': 18, 'sex': 'male'} dic.pop('age') print(dic) # {'sex': 'male'} dic.clear() print(dic) # {}
dic = {'name':'fsd', 'age':18, 'sex':'male'} print(len(dic)) # 3 print(dic.keys()) # dict_keys(['name', 'age', 'sex']) for i in dic.keys(): print(i) # name # age # sex for i in dic.values(): print(i) # fsd # 18 # male for i in dic.items(): print(i) # ('name', 'fsd') # ('age', 18) # ('sex', 'male')
#集合,无序性 set1 = {'a','b','c','d','e','f','g','h'} print(set1) {'d', 'g', 'e', 'a', 'c', 'f', 'b', 'h'}
set2 = {1,2,3,4,5} print("原来的",set2) set2.add(6) print(set2) set2.update({6,7}) print(set2) # {1, 2, 3, 4, 5, 6, 7} set2.update("89") print(set2) # {1, 2, 3, 4, 5, 6, 7, '9', '8'} set2.remove(6) print(set2) # {1, 2, 3, 4, 5, 7, '9', '8'} set2.pop() print(set2) # {2, 3, 4, 5, 7, '9', '8'} set2.discard(4) print(set2) # {2, 3, 5, 7, '8', '9'}
set1 = {1,3,6,8} set2 = {1,5,8} print(set1&set2) # {8, 1} print(set1|set2) # {1, 3, 5, 6, 8}
print(eval('1+1')) # 2
import copy list = [1,2,3] list2 = list print(list) print(list2) list2.append(4) print(list) # [1, 2, 3, 4] print(list2) # [1, 2, 3, 4] list3 = copy.copy(list) print(list3) list.append(5) print(list) # [1, 2, 3, 4, 5] print(list3) # [1, 2, 3, 4] #深拷贝数据变化只影响自己 list4 = [1,2,[5,6]] list5 = copy.deepcopy(list4) print(list5) list4.append(7) print(list5) # [1, 2, [5, 6]] print(list4) # [1, 2, [5, 6], 7]
def login(): print("denglu") login()
def buy(): return 0 print(buy()) def add(a,b): return a+b print(add(1,2))
def func(a=1): print(a) func() func(5) # 5 def func2(*args): print(args) print(type(args)) func2(1) # <class 'tuple'> def func3(**kwargs): print(kwargs) print(type(kwargs)) func3() func3(name = 'ff',age = 10) # {'name': 'ff', 'age': 10} # <class 'dict'>
add = lambda a,b: a+b print(add(1,2))
add = lambda a,b: a+b print(add(1,2))