Question

我用Pandas创建了一个3列的DataFrame，而我只是试图访问特定行的内容（里面有一个字符串）。

In [1]: from subprocess import check_output, STDOUT

In [2]: print check_output(["snmpwalk", "-V"], stderr=STDOUT, shell=True)
---------------------------------------------------------------------------
CalledProcessError                        Traceback (most recent call last)
<ipython-input-2-9886fda8a591> in <module>()
----> 1 print check_output(["snmpwalk", "-V"], stderr=STDOUT, shell=True)

/usr/lib/python2.7/subprocess.pyc in check_output(*popenargs, **kwargs)
    571         if cmd is None:
    572             cmd = popenargs[0]
--> 573         raise CalledProcessError(retcode, cmd, output=output)
    574     return output
    575 

CalledProcessError: Command '['snmpwalk', '-V']' returned non-zero exit status 1

In [3]: print check_output(["/usr/bin/snmpwalk", "-V"], stderr=STDOUT, shell=True)
---------------------------------------------------------------------------
CalledProcessError                        Traceback (most recent call last)
<ipython-input-3-25c11cea9013> in <module>()
----> 1 print check_output(["/usr/bin/snmpwalk", "-V"], stderr=STDOUT, shell=True)

/usr/lib/python2.7/subprocess.pyc in check_output(*popenargs, **kwargs)
    571         if cmd is None:
    572             cmd = popenargs[0]
--> 573         raise CalledProcessError(retcode, cmd, output=output)
    574     return output
    575 

CalledProcessError: Command '['/usr/bin/snmpwalk', '-V']' returned non-zero exit status 1

我认为tweets = pd.DataFrame() tweets['text'] = map(lambda tweet: tweet['text'], tweets_data) tweets['lang'] = map(lambda tweet: tweet['lang'], tweets_data) tweets['country'] = map(lambda tweet: tweet['place']['country'] if tweet['place'] != None else None, tweets_data)或tweets['text',0]可行，但情况并非如此

Answer 1

如果您正在寻找特定的刺痛，可以使用str.contains。它的工作原理如下：

获取数据

  SELECT TOP(1)  [Symbol],[TargetPosition]
  FROM [FX].[dbo].[Orders] 
  GROUP BY [Symbol]
  ORDER BY [OrderUTC]

使用import pandas as pd from io import StringIO data = """ id tweet 12 "this is the first tweet" 34 "this is the second tweet" 48 "this is the third tweet" 59 "finally the fourth tweet" """ df = pd.read_csv(StringIO(data), delimiter='\s+')

str.contains

这将导致：

first = df['tweet'].str.contains('first')
this = df['tweet'].str.contains('this')
fin = df['tweet'].str.contains('finally')

如何访问DataFrame中的特定行

1 个答案: