Pandas Python - 在aggegate(csv文件)中将HH:MM:SS转换为秒

Question

我试图转换'平均数字'中的数字.会话持续时间'(HH:MM:SS)列到Pandas read_csv模块/功能中的整数(以秒为单位).例如,'0:03:26'将在转换后206秒.

输入示例:

Source       Month  Sessions    Bounce Rate     Avg. Session Duration   
ABC.com     201501   408        26.47%           0:03:26 
EFG.com     201412   398        31.45%           0:04:03

我写了一个函数:

def time_convert(x):
    times = x.split(':')
    return (60*int(times[0])+60*int(times[1]))+int(times[2])

只需将"0:03:26"传递给函数,此功能就可以正常工作.但是当我试图通过将函数应用到Pandas中的另一列时创建一个新列'Duration',

df = pd.read_csv('myfile.csv')
df['Duration'] = df['Avg. Session Duration'].apply(time_convert)

它返回了一条错误消息:

> --------------------------------------------------------------------------- AttributeError                            Traceback (most recent call
> last) <ipython-input-53-01e79de1cb39> in <module>()
> ----> 1 df['Avg. Session Duration'] = df['Avg. Session Duration'].apply(lambda x: x.split(':'))
> 
> /Users/yumiyang/anaconda/lib/python2.7/site-packages/pandas/core/series.pyc
> in apply(self, func, convert_dtype, args, **kwds)    1991            
> values = lib.map_infer(values, lib.Timestamp)    1992 
> -> 1993         mapped = lib.map_infer(values, f, convert=convert_dtype)    1994         if len(mapped) and
> isinstance(mapped[0], Series):    1995             from
> pandas.core.frame import DataFrame
> 
> /Users/yumiyang/anaconda/lib/python2.7/site-packages/pandas/lib.so in
> pandas.lib.map_infer (pandas/lib.c:52281)()
> 
> <ipython-input-53-01e79de1cb39> in <lambda>(x)
> ----> 1 df['Avg. Session Duration'] = df['Avg. Session Duration'].apply(lambda x: x.split(':'))
> 
> AttributeError: 'float' object has no attribute 'split'

我不知道为什么它会说'平均值'.会话持续时间'是浮动的.

Data columns (total 7 columns):
Source                   250 non-null object
Time                     251 non-null object
Sessions                 188 non-null object
Users                    188 non-null object
Bounce Rate              188 non-null object
Avg. Session Duration    188 non-null object
% New Sessions           188 non-null object
dtypes: object(7)

有人可以帮我找出问题所在吗？

Answer 1

df['Avg. Session Duration'] 应该是您的功能工作的字符串.

df =pd.DataFrame({'time':['0:03:26']})

def time_convert(x):
    h,m,s = map(int,x.split(':'))
    return (h*60+m)*60+s

df.time.apply(time_convert)

这对我来说很好.

Answer 2

该错误意味着该列被识别为浮点数，而不是字符串。修复读取数据的方式，例如：

#!/usr/bin/env python
import sys
import pandas

def hh_mm_ss2seconds(hh_mm_ss):
    return reduce(lambda acc, x: acc*60 + x, map(int, hh_mm_ss.split(':')))

df = pandas.read_csv('input.csv', sep=r'\s{2,}',
                     converters={'Avg. Session Duration': hh_mm_ss2seconds})
print(df)

输出

    Source   Month  Sessions Bounce Rate  Avg. Session Duration
0  ABC.com  201501       408      26.47%                    206
1  EFG.com  201412       398      31.45%                    243

[2 rows x 5 columns]