Python语言基础与应用 (P16)上机练习：基本数据类型

本文是笔者在学习MOOC课程《Python语言基础与应用》 （北京大学-陈斌）中根据上机课时的要求写下在代码

课程总链接：

中国大学MOOC

B站

本节课链接

数值基本运算： 33和7
+, -, *, /, //, %, **
hex(), oct(), bin()

 Python 3.7.0 (default, Jun 28 2018, 08:04:48) [MSC v.1912 64 bit (AMD64)] :: Anaconda, Inc. on win32
 Type "help", "copyright", "credits" or "license" for more information.
 >>> 33+7
 40
 >>> 33-7
 26
 >>> 33*7
 231
 >>> 33/7
 4.714285714285714
 >>> 33//7
 4
 >>> 33%7
 5
 >>> 33**7
 42618442977
 >>> 7**33
 7730993719707444524137094407
 >>> 33**33
 129110040087761027839616029934664535539337183380513
 >>> hex(33)
 '0x21'
 >>> hex(7)
 '0x7'
 >>> oct(7)
 '0o7'
 >>> oct(33)
 '0o41'
 >>> bin(33)
 '0b100001'
 >>> bin(7)
 '0b111'

类型转换
1， 0， 'abc', None, 1.2, False, ''
str(), bool(), int(), float()
is None, ==, !=

 >>> str(1)
 ''
 >>> str(0)
 ''
 >>> bool(1)
 True
 >>> bool(0)
 False
 >>> bool('abc')
 True
 >>> int('abc')
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 ValueError: invalid literal for int() with base 10: 'abc'
 >>> int('a')
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 ValueError: invalid literal for int() with base 10: 'a'
 >>> float('abc')
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 ValueError: could not convert string to float: 'abc'
 >>> float(1)
 1.0
 >>> str(None)
 'None'
 >>> int(None)
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'
 >>> int('None')
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 ValueError: invalid literal for int() with base 10: 'None'
 >>> int(1.2)
 1
 >>> int(False)
 0
 >>> int(True)
 1
 >>> float('')
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 ValueError: could not convert string to float:
 >>> bool('')
 False
 >>> 1 is None
 False
 >>> 0 is None
 False
 >>> '' is None
 False
 >>> 1==1.2
 False
 >>> False is None
 False
 >>> True is None
 False

字符串基本操作
+, *, len(), [], in
ord(), chr()
含有中文的字符串

 >>> a='Congratulations'
 >>> b='misunderstandings'
 >>> a+b
 'Congratulationsmisunderstandings'
 >>> a+' '+b
 'Congratulations misunderstandings'
 >>> len(a)
 15
 >>> len(b)
 17
 >>> c in a
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 NameError: name 'c' is not defined
 >>> 'c' in a
 False
 >>> 's' in b
 True
 >>> 'C' in a
 True
 >>> [a]
 ['Congratulations']
 >>> ord('a')
 97
 >>> chr(86)
 'V'
 >>> ord(a)
 Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
 TypeError: ord() expected a character, but string of length 15 found
 >>> c='你好'
 >>> d='国'
 >>> len(c)
 2
 >>> len(d)
 1
 >>> ord(d)
 22269
 >>> chr(83475)
 '