Python 基础(1) string

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Table of Contents

• 1  string编辑
  • 1.1  修整截断头尾strip()
  • 1.2  右截断、左截断
• 2  in 和 not in 操作
• 3  The upper(), lower(), isupper(), islower() string methods
• 4  string template 字符串模板
• 5  Pyperclip
• 6  string编码和解码
  • 6.1  编码（bytes to string）
    • 6.1.1  chr(i) buildin function 将制定整数unicode编码返回对应的字符string
    • 6.1.2  bytes.decode(encoding=”utf-8”, errors=”strict”)
    • 6.1.3  str(object=b’’, encoding=’utf-8’, errors=’strict’) buildin function
  • 6.2  解码（string to bytes）
    • 6.2.1  ord(c) buildin function
    • 6.2.2  str.encode(self, /, encoding=’utf-8’, errors=’strict’) 将string返回默认utf8 unicode字节
    • 6.2.3  class bytes([source[, encoding[, errors]]]) buildin function

string编辑

修整截断头尾strip()

str.strip([chars]) 去掉字符串左右两端的空格，返回字新的字符串对象

'''
Return a copy of the string with leading and trailing whitespace remove.
If chars is given and not None, remove characters in chars instead.
'''
check = '    Everything is fine!     '
check.strip()

'Everything is fine!'

如果chars参数指定了，则从字符串两端计算删除指定的 chars 的成员

#删除字符串两端的[E][e][v][!][ ]
check.strip('Eev! ')

'rything is fin'

右截断、左截断

• 右删除str.rstrip([chars])
• 左删除str.lstrip([chars])

in 和 not in 操作

'Python' in 'Python is great!'

True

'PYTHON' in 'Python is great!'

False

'' in 'Python is great!'

True

'python' not in 'python and javascript' ## Matches case

False

• The in and not in Operators with list

a = ['P', 'y', 't', 'h', 'o', 'n']
'p' in a

False

The upper(), lower(), isupper(), islower() string methods

string template 字符串模板

• 可以预先定义sting模板，然后给模板中的制定替换文字做文字替换操作

from string import Template #先引入 string.Template
language = 'Python'
t = Template('$lang is great! $name likes play with $lang')
t.substitute(lang=language, name='Dummy') ## Substitutes name with language variable

'Python is great! Dummy likes play with Python'

Pyperclip

• Pyperclip is python library that help us easily copy and paste string
• First Install it using pip

pip install pyperclip

import pyperclip
pyperclip.copy('Hello World') ## Copy Hello World
pyperclip.paste()

string编码和解码

编码（bytes to string）

chr(i) buildin function 将制定整数unicode编码返回对应的字符string

print(chr(97))

a

bytes.decode(encoding="utf-8", errors="strict")

• 根据bytes返回默认utf8编码字符串

b'\xe6\x88\x91\xe4\xbb\xac'.decode()

'我们'

str(object=b'', encoding='utf-8', errors='strict') buildin function

• 根据bytes返回制定编码方式的字符串

str(b'\xe6\x88\x91\xe4\xbb\xac', 'utf8')

'我们'

解码（string to bytes）

ord(c) buildin function

• 根据给定的字符，返回代表该字符的unicode十进制整数编码

print(ord('a'))
print(ord('我'))

97
25105

str.encode(self, /, encoding='utf-8', errors='strict') 将string返回默认utf8 unicode字节

• 返回bytes对象

'我们'.encode()

b'\xe6\x88\x91\xe4\xbb\xac'

class bytes([source[, encoding[, errors]]]) buildin function

bytes('我们', 'utf8')

b'\xe6\x88\x91\xe4\xbb\xac'