Python字符串练习

#1字符串:格式化输出、字符串分割、字符串搜索、连接
from math import pi

import string
"""
format_test = "2017 %% %s %s %.3f"
value = ("hello","world",pi)
print(format_test % value)

#简单转换
str1 = "The egg is $%d %x %f %i %r %.1f %5.3f,%.5s" % (42,15,pi,pi,42,pi,pi,"123456789")
print(str1)
#符号对齐0填充
str2 = "%010.3f" % (pi)
str3 = "%-10.3f" % (pi)
print(str2)
print("左对齐",str3,"右侧空格")
str4 = "% 5d" % 10 , "%+5d" % -10, "%+5d" % 10
print(str4)

width = input("please input your ")
price_width = 10
item_width = int(width) - price_width
header_format = "%-*s%*s"#*作为字段宽度或精度宽度会从元组读取(%-25s左对齐右侧空格补齐 %10s)
format = "%-*s%*.2f"
print("="*int(width))
print(header_format % (item_width,"item",price_width,"price"))
print("-"*int(width))
print(format%(item_width,"Apple",price_width,0.4))
print(format%(item_width,"Apple",price_width,0.4))
print(format%(item_width,"Apple",price_width,0.4))
print(format%(item_width,"Apple",price_width,0.4))
print(format%(item_width,"Apple",price_width,0.4))
print("-"*int(width))
print("="*int(width))
"""

"""
输出结果
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
2017 % hello world 3.142
The egg is $42 f 3.141593 3 42 3.1 3.142,12345
000003.142
左对齐 3.142 右侧空格
(' 10', ' -10', ' +10')
please input your 100
====================================================================================================
item price
----------------------------------------------------------------------------------------------------
Apple 0.40
Apple 0.40
Apple 0.40
Apple 0.40
Apple 0.40
----------------------------------------------------------------------------------------------------
====================================================================================================
"""



"""
#2find方法:查找子串返回子串所在位置最左侧索引,没找到返回-1
str5 = "hello world welcome you are good hello"
print(str5.find("you"))
print(str5.find("your"))
print(str5.find("he"))
print(str5.find("hello"))
print(str5.find("we"))
print(str5.find("llo",3))#3为从起始点3开始查找
print(str5.find("llo",3,30))#3,30为从起始点3到结束点30之间查找
"""

"""
输出结果
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
20
-1
0
0
12
35
-1
"""

"""
#3 join方法:在队列中添加元素
str6 = ['1','2','3','4']#队列元素必须是字符串,不能是数字
str7 = "+"
print("连接字符串",str7.join(str6))
"""
"""
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
连接字符串 1+2+3+4
"""

"""
#4 lower:返回字符串的小写版
str7 = "Hello World Welcome You Are Good"
print("返回小写字母:",str7.lower())
#查找names
name = "Hello"
names = ["hello","Hi","world"]
if name.lower() in names :
print("Find it")
#title:所有单词首字母大写
print("welcome to china that's very good".title())
print(string.capwords("welcome to china that's very good"))
"""

"""
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
返回小写字母: hello world welcome you are good
Find it
Welcome To China That'S Very Good
Welcome To China That's Very Good
"""

"""
#5 replace 返回匹配替换后的字符串
str7 = "Hello World HeHe"
print("字符串替换后",str7.replace("HeHe","!"))
"""

"""
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
字符串替换后 Hello World !
"""

"""
#6 split:将字符串分割成序列
print("1+2+3+4+5+6+7".split("+"))
print("D:嵌入式-书籍中转站编程书籍".split('\'))
print("以空格或者制表符分割:","12 34 56 78 0".split())
"""

"""
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
['1', '2', '3', '4', '5', '6', '7']
['D:', '嵌入式-书籍中转站', '编程书籍']
以空格或者制表符分割: ['12', '34', '56', '78', '0']
"""

"""
#7 strip:除去两侧的空格(不包含内部)
print(" Hello World ".strip())
print("除去两侧指定的字符:","###**** Hello *** world ***###!".strip("*!#"))
"""

"""
C:python3.7python.exe D:/Python-Test/qiubai/qiubai/Test2.py
Hello World
除去两侧指定的字符: Hello *** world
"""

"""
#8 translate:替换字符串中的某些部分,只处理单个字符,可以同时替换多个
from string import maketrans # 引用 maketrans 函数。

intab = "aeiou"
outtab = "12345"
trantab = maketrans(intab, outtab)

str = "this is string example....wow!!!";
print str.translate(trantab);
"""

"""
th3s 3s str3ng 2x1mpl2....w4w!!!
"""
原文地址:https://www.cnblogs.com/acer-haitao/p/7262126.html