在日常编程中，对字符串的操作往往是比较频繁的。Python给我们内置一些比较常用的方法。来方便我们日常的操作。下面我这边博客就将字符串的一些常用方法进行罗列出来。方便大家在使用的时候查询。

常用功能

startswith()判断字符串是否以XX开头，得到一个布尔值

v1 = "叨逼叨的一天，烦死了"

# True
result = v1.startswith("叨逼叨的一天")

print(result) # 值为True

endswith()判断字符串是否以XX结尾，等到一个布尔值

v1 = "叨逼叨的一天，烦死了"

result = v1.endswith("烦死了")

print(result) # 值为True

isdecimal()判断字符串是否是十进？得到一个布尔值

v1 = "1238871"
result = v1.isdecimal()
print(result) # True

isdigit()判断字符串是否是数字？得到一个布尔值

str = "123456";  # Only digit in this string
print str.isdigit();

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

strip()去除字符串两边的 空格、换行符、制表符，得到一个新字符串

lstrip()删除左侧

rstrip()删除右侧

data = input("请输入内容：") #武沛齐,武沛齐   
print(data)

msg = " H e ll o啊，树哥 "
data = msg.strip()
print(data) # 将msg两边的空白去掉，得到"H e ll o啊，树哥"

msg = " H e ll o啊，树哥 "
data = msg.lstrip()
print(data) # 将msg左边的空白去掉，得到"H e ll o啊，树哥 "

msg = " H e ll o啊，树哥 "
data = msg.rstrip()
print(data) # 将msg右边的空白去掉，得到" H e ll o啊，树哥"

删除两边指定内容

msg = "哥H e ll o啊，树哥"
data = msg.strip("哥")
print(data) # 将msg两边的空白去掉，得到"H e ll o啊，树"

msg = "哥H e ll o啊，树哥"
data = msg.lstrip("哥")
print(data) # 将msg左边的空白去掉，得到"H e ll o啊，树哥"

msg = "哥H e ll o啊，树哥"
data = msg.rstrip("哥")
print(data) # 将msg右边的空白去掉，得到"哥H e ll o啊，树"

upper()字符串变大写，得到一个新字符串

msg = "my name is oliver queen"
data = msg.upper()

print(msg) # my name is oliver queen
print(data) # 输出为：MY NAME IS OLIVER QUEEN

capitalize() 字符串首字母变大写

>>>s = 'a, B'
>>> s.capitalize()
'A, b'
 
>>> s = ' a, B'    # a 前面有空格
>>> s.capitalize()
' a, b'
 
>>> s = 'a, BCD'
>>> s.capitalize()
'A, bcd'

lower()字符串变小写，得到一个新字符串

msg = "My Name Is Oliver Queen"
data = msg.lower()

print(data) # 输出为：my name is oliver queen

replace（）字符串内容替换，得到一个新的字符串

data = "你是个好人，但是好人不合适我"
value = data.replace("好人","贱人")
print(data)  # "你是个好人，但是好人不合适我"
print(value) # "你是个贱人，但是贱人不合适我"

一个典型的屏蔽案例

char_list = ["吗","逗比","二蛋","钢球"]    # 创建一个数组用于存放需要屏蔽的词语

content = input("请输入评论信息")    # 输入句子
for item in char_list:    # 循环char_list列表
  content = content.repalce(item,"**")    # 将词语屏蔽得到一个新的句子content

print(content)

split（）字符串切割得到一个列表

data = "武沛齐|root|wupeiqi@qq.com"
result = data.split('|') # ["武沛齐","root","wupeiqi@qq.com"]
print(data) # "武沛齐|root|wupeiqi@qq.com"
print(result) # 输出 ["武沛齐","root","wupeiqi@qq.com"] 根据特定字符切开之后保存在列表中，方便以后的操作

可切割列表长度

data = "武沛齐|root|wupeiqi@qq.com"
v1 = data.split("|")   # ['武沛齐', 'root', 'wupeiqi@qq.com']
print(v1)

v2 = data.split("|", 2) # ['武沛齐', 'root|wupeiqi@qq.com']
print(v2)

rsplit()切割位置

data = "武沛齐,root,wupeiqi@qq.com"

v1 = data.rsplit(',')
print(v1) # ['武沛齐', 'root', 'wupeiqi@qq.com']

v2 = data.rsplit(',',1)
print(v2) # ['武沛齐,root', 'wupeiqi@qq.com']

join()字符串拼接，得到一个新的字符串

data_list = ["alex","是","大烧饼"]
v1 = "_".join(data_list) # alex_是_大烧饼
print(v1)

count()统计字符串里某个字符或子字符串出现的次数

str = "this is string example....wow!!!";
 
sub = "i";
print "str.count(sub, 4, 40) : ", str.count(sub, 4, 40)
sub = "wow";
print "str.count(sub) : ", str.count(sub)