目录
1.怎么存数据
2.怎么用数据
3.函数
4. 类和对象
4.1. 定义类的模板
4.2.继承
4.3 多态
5. IO文件操作和OS目录操作
OS操作
IO文件
6. 正则表达式及re模块的使用
6.2. re模块的使用
变量: age =10
字符串: name = "python"
列表: [1,2,3,"python"]
元组: (1,2,3)（不可以更改）
字典: {"a":100, "b":"666"}
数字操作符： +、-、*、/、%、//、**
判断循环:
if a>10: b = a + 20 if b>20: pass elif: a>8: pass else: pass
while循环
if判断:
while i<5: # do something pass i = i + 1 while true: pass
# 位置参数
def person(name, age):
print(name,age)
# 默认参数
def person(name,age=20):
print(name, age)
# 关键字参数
def person(name, age, **kw):
print('name:', name, 'age:', age, 'other:', kw)
person('hao', 20) # name: Michael age: 30 other: {}
person('hao', 20, gener = 'M', job = 'Engineer') # name: Adam age: 45 other: {'gender': 'M', 'job': 'Engineer'}
extra = {'city': 'Beijing', 'job': 'Engineer'}
person('Jack', 24, **extra)
# 命名关键字参数
def person(name, age, *, city='Beijing', job):
print(name, age, city, job)
person('Jack', 24, job = '123')
person('Jack', 24, city = 'Beijing', job = 'Engineer')
# Combination
# 可变 + 关键字参数
def f1(a, b, c=0, *args, **kw):
print('a =', a, 'b =', b, 'c =', c, 'args =', args, 'kw =', kw)
f1(1, 2, 3, 'a', 'b') # a = 1 b = 2 c = 3 args = ('a', 'b') kw = {'x': 99}
f1(1, 2, 3, 'a', 'b', x=99) # a = 1 b = 2 c = 0 d = 99 kw = {'ext': None}
# 默认参数 + 命名关键字参数 + 关键字参数
def f2(a, b, c=0, *, d, **kw):
print('a =', a, 'b =', b, 'c =', c, 'd =', d, 'kw =', kw)
f2(1, 2, d=99, ext=None) # a = 1 b = 2 c = 0 d = 99 kw = {'ext': None}class Student(object):
def __init__(self, name, score):
self.__name = name
self.__score = score
# print(mike)
def __str__(self):
msg = "name: " + self.__name + "score: " + str(self.__score)
return msg
# mike
__repr__ = __str__
# mike()
__call__ = __str__
@property
def name(self):
return self.__name
@name.setter
def name(self, value):
if type(value) == str:
self.__name = value
else:
raise ValueError('Bad name')
@property
def score(self):
return self.__score
@score.setter
def score(self, value):
if 0 <= value <= 100:
self.__score = value
else:
raise ValueError('Bad score')
def final_report(self):
if self.__score >= 90:
level = 'A'
elif self.__score >= 70:
level = 'B'
elif self.__score >= 60:
level = 'C'
else:
level = 'D'
msg = "Your final value is: " + level
return msg
# 调用
mike = Student('mike', 85)
print("-" * 20 + "Print property" + "-" * 20)
print(mike)
print("name: %s" % (mike.name))
print("-" * 30 + "Print methods" + "-" * 20)
print(mike.final_report())
print("-" * 30 + "Print modified infor" + "-" * 20)
mike.name = "Obama"
mike.score = 50
print("-" * 30)
print("modified name: %s" % (mike.name))--------------------Print property-------------------- name: mikescore: 85 name: mike ------------------------------Print methods-------------------- Your final value is: B ------------------------------Print modified infor-------------------- ------------------------------ modified name: Obama
class SixGrade(Student):
def __init__(self, name, score, grade):
super().__init__(name, score)
self.__grade = grade
# grade是一个只读属性
@property
def grade(self):
return self.__grade
def final_report(self, comments):
# 子类中调用父类方法
text_from_Father = super().final_report()
print(text_from_Father)
msg = "commants from teacher: " + comments
print(msg)
print("-" * 20 + "继承" + "-" * 20)
fangfang = SixGrade('fang', 95, 6)
fangfang.final_report("You are handsome")
print(fangfang.grade)--------------------继承-------------------- Your final value is: A commants from teacher: You are handsome 6
class SixGrade(Student):
pass
class FiveGrade(Student):
pass
def print_level(Student):
msg = Student.final_report()
print(msg)
print_level(Student('from class', 90))
print_level(SixGrade('from subclass-1', 56))
print_level(FiveGrade('from subclass-2', 85))Your final value is: A Your final value is: D Your final value is: B
import os
# 获取当前目录的绝对路径
path = os.path.abspath('.')
# 创建一个目录
os.path.join('/Users/michael', 'testdir')
os.mkdir('/Users/michael/testdir')
# 删除一个目录
os.rmdir('/Users/michael/testdir')
# 拆分路径
os.path.split('/Users/michael/testdir/file.txt') # ('/Users/michael/testdir', 'file.txt')
os.path.splitext('/path/to/file.txt') # ('/path/to/file', '.txt')
# 重命名
os.rename('test.txt', 'test.py')
# 删除文件
os.remove('test.py')
# 列出所有python文件
[x for x in os.listdir('.') if os.path.isfile(x) and os.path.splitext(x)[1]=='.py']| 方法 | 特性 | 性能 |
|---|---|---|
read() | 读取全部内容 | 一般 |
readline() | 每次读出一行内容 | 占用内存最少 |
readlines() | 读取整个文件所有行，保存在一个列表(list)变量中，每行作为一个元素 | 最好(内存足) |
write() | 写文件 |
# 读
# 下面是read()方法的使用，“r”表示read
with open('testRead.txt', 'r', encoding='UTF-8') as f1:
results = f1.read() # 读取数据
print(results)
# 下面是readline()方法的使用，“r”表示read
with open('testRead.txt', 'r', encoding='UTF-8') as f2:
line = f2.readline() # 读取第一行
while line is not None and line != '':
print(line)
line = f2.readline() # 读取下一行
# 下面是readlines()方法的使用，“r”表示read
with open('testRead.txt', 'r', encoding='UTF-8') as f3:
lines = f3.readlines() # 接收数据
for line in lines: # 遍历数据
print(line)
# 写
with open('/User/test.txt', 'w') as f:
f.write('hello')主要参考资料为：
内置的 re 模块来使用正则表达式，提供了很多内置函数：
pattern = re.compile(pattern[, flag]):
参数：
pattern: 字符串形式的正则
flag: 可选模式，表示匹配模式
例子：
import re pattern = re.compile(r'd+')
Pattern的常用方法
import re
pattern = re.compile(r'd+')
m0 = pattern.match('one12twothree34four')
m = pattern.match('one12twothree34four', 3, 10)
print("-" * 15 + "Match methods" + "-" * 15)
print("found strings: ", m.group(0))
print("start index of found strings: ", m.start(0))
print("end index of found strings: ", m.end(0))
print("Span length of found strigns: ", m.span(0))
s = pattern.search('one12twothree34four')
print("-" * 15 + "Search methods" + "-" * 15)
print("found strings: ", s.group(0))
print("start index of found strings: ", s.start(0))
print("end index of found strings: ", s.end(0))
print("Span length of found strigns: ", s.span(0))
f = pattern.findall('one1two2three3four4', 0, 10)
print("-" * 15 + "findall methods" + "-" * 15)
print("found strings: ", f)
f_i = pattern.finditer('one1two2three3four4', 0, 10)
print("-" * 15 + "finditer methods" + "-" * 15)
print("type of method: ", type(f_i))
for m1 in f_i: # m1 是 Match 对象
print('matching string: {}, position: {}'.format(m1.group(), m1.span()))
p = re.compile(r'[s,;]+')
print("-" * 15 + "Split methods" + "-" * 15)
print("split a,b;c.d: ", p.split('a,b;; c d'))
p1 = re.compile(r'(w+) (w+)')
s1 = 'hello 123, hello 456'
def func(m):
return 'hi' + ' ' + m.group(2)
print("-" * 15 + "替换 methods" + "-" * 15)
print(p1.sub(r'hello world', s1)) # 使用 'hello world' 替换 'hello 123' 和 'hello 456'
print(p1.sub(r'2 1', s1)) # 引用分组
print(p1.sub(func, s1))
print(p1.sub(func, s1, 1)) # 最多替换一次结果是:
---------------Match methods--------------- found strings: 12 start index of found strings: 3 end index of found strings: 5 Span length of found strigns: (3, 5) ---------------Search methods--------------- found strings: 12 start index of found strings: 3 end index of found strings: 5 Span length of found strigns: (3, 5) ---------------findall methods--------------- found strings: ['1', '2'] ---------------finditer methods--------------- type of method: <class 'callable_iterator'> matching string: 1, position: (3, 4) matching string: 2, position: (7, 8) ---------------Split methods--------------- split a,b;c.d: ['a', 'b', 'c', 'd'] ---------------替换 methods--------------- hello world, hello world 123 hello, 456 hello hi 123, hi 456 hi 123, hello 456
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