有关字符串基本方法
大家好，我又回来了！ 之前的几期我们已经简单了解了pandas的基础操作，但是只要涉及到数据，最常见的就是String（字符串）类型，所以很多时候我们其实都在和字符串打交道，所以今天，我会把我自己总结的，有关字符串的常用方法分享给大家，希望能够帮到各位小伙伴~
Split and format
latitude = '37.24N'
longitude = '-115.81W'
'Coordinates {0},{1}'.format(latitude,longitude)
>>> 'Coordinates 37.24N,-115.81W'f'Coordinates {latitude},{longitude}'
>>>'Coordinates 37.24N,-115.81W''{0},{1},{2}'.format(*('abc'))
>>>'a,b,c'coord = {"latitude":latitude,"longitude":longitude}
'Coordinates {latitude},{longitude}'.format(**coord)
>>>'Coordinates 37.24N,-115.81W'Access argument' s attribute
class Point:
def __init__(self,x,y):
self.x,self.y = x,y
def __str__(self):
return 'Point({self.x},{self.y})'.format(self = self)
def __repr__(self):
return f'Point({self.x},{self.y})'test_point = Point(4,2)
test_point
>>> Point(4,2)str(Point(4,2))
>>>'Point(4,2)'Replace with %s , %r :
" repr() shows the quote {!r}, while str() doesn't:{!s} ".format('a1','a2')
>>> " repr() shows the quote 'a1', while str() doesn't:a2 "
Align :
'{:<30}'.format('left aligned')
>>>'left aligned ''{:>30}'.format('right aligned')
>>>' right aligned''{:^30}'.format('centerd')
>>>' centerd ''{:*^30}'.format('centerd')
>>>'***********centerd************'Replace with %x , %o :
"int:{0:d}, hex:{0:x}, oct:{0:o}, bin:{0:b}".format(42)
>>>'int:42, hex:2a, oct:52, bin:101010''{:,}'.format(12345677)
>>>'12,345,677'Percentage :
points = 19
total = 22
'Correct answers: {:.2%}'.format(points/total)
>>>'Correct answers: 86.36%'Date :
import datetime as dt
f"{dt.datetime.now():%Y-%m-%d}"
>>>'2019-03-27'f"{dt.datetime.now():%d_%m_%Y}"
>>>'27_03_2019'today = dt.datetime.today().strftime("%d_%m_%Y")
today'27_03_2019'
Split without parameters :
"this is a test".split()
>>>['this', 'is', 'a', 'test']Concatenate :
'do'*2
>>>'dodo'orig_string ='Hello'
orig_string+',World'
>>>'Hello,World'full_sentence = orig_string+',World'
full_sentence
>>>'Hello,World'Check string type , slice，count，strip :
strings = ['do','re','mi']
', '.join(strings)
>>>'do, re, mi''z' not in 'abc'
>>> Trueord('a'), ord('#')
>>> (97, 35)chr(97)
>>>'a's = "foodbar"
s[2:5]
>>>'odb's[:4] + s[4:]
>>>'foodbar's[:4] + s[4:] == s
>>>Truet=s[:]
id(s)
>>>1547542895336id(t)
>>>1547542895336s is t
>>>Trues[0:6:2]
>>>'fob's[5:0:-2]
>>>'ado's = 'tomorrow is monday'
reverse_s = s[::-1]
reverse_s
>>>'yadnom si worromot's.capitalize()
>>>'Tomorrow is monday's.upper()
>>>'TOMORROW IS MONDAY's.title()
>>>'Tomorrow Is Monday's.count('o')
>>> 4"foobar".startswith('foo')
>>>True"foobar".endswith('ar')
>>>True"foobar".endswith('oob',0,4)
>>>True"foobar".endswith('oob',2,4)
>>>False"My name is yo, I work at SG".find('yo')
>>>11# If can't find the string, return -1
"My name is ya, I work at Gener".find('gent')
>>>-1
# Check a string if consists of alphanumeric characters
"abc123".isalnum()
>>>True"abc%123".isalnum()
>>>False"abcABC".isalpha()
>>>True"abcABC1".isalpha()
>>>False'123'.isdigit()
>>>True'123abc'.isdigit()
>>>False'abc'.islower()
>>>True"This Is A Title".istitle()
>>>True"This is a title".istitle()
>>>False'ABC'.isupper()
>>>True'ABC1%'.isupper()
>>>True'foo'.center(10)
>>>' foo '' foo bar baz '.strip()
>>>'foo bar baz'' foo bar baz '.lstrip()
>>>'foo bar baz '' foo bar baz '.rstrip()
>>>' foo bar baz'"foo abc foo def fo ljk ".replace('foo','yao')
>>>'yao abc yao def fo ljk '
'www.realpython.com'.strip('w.moc')
>>>'realpython''www.realpython.com'.strip('w.com')
>>>'realpython''www.realpython.com'.strip('w.ncom')
>>>'realpyth'Convert to lists :
', '.join(['foo','bar','baz','qux'])
>>>'foo, bar, baz, qux'list('corge')
>>>['c', 'o', 'r', 'g', 'e']':'.join('corge')
>>>'c:o:r:g:e''www.foo'.partition('.')
>>>('www', '.', 'foo')'foo@@bar@@baz'.partition('@@')
>>>('foo', '@@', 'bar@@baz')'foo@@bar@@baz'.rpartition('@@')
>>>('foo@@bar', '@@', 'baz')'foo.bar'.partition('@@')
>>>('foo.bar', '', '')# By default , rsplit split a string with white space
'foo bar adf yao'.rsplit()
>>>['foo', 'bar', 'adf', 'yao']'foo.bar.adf.ert'.split('.')
>>>['foo', 'bar', 'adf', 'ert']'foo\nbar\nadfa\nlko'.splitlines()
>>>['foo', 'bar', 'adfa', 'lko']总结
除了我以上总结的这些，还有太多非常实用的方法，大家可以根据自己的需求去搜索啦！
我把这一期的ipynb文件和py文件放到了Github上，大家如果想要下载可以点击下面的链接：
- Github仓库地址： https://github.com/yaozeliang/pandas_share
希望大家能够继续支持我，完结，撒花