从文本中提取Age值以在pandas中创建新列

时间:2018-02-19 06:53:50

标签: python regex python-3.x pandas

我有一个数据集如下:

df=pd.DataFrame([["Sam is 5", 2000],["John is 3 years and 6 months",1200],["Jack is 4.5 years",7000],["Shane is 25 years old",2000]], columns = ['texts','amount'])

print(df)

    texts                          amount
0   Sam is 5                        2000
1   John is 3 years and 6 months    1200
2   Jack is 4.5 years               7000
3   Shane is 25 years old           2000

我想从df['texts']中提取年龄值,并使用它来计算新列df['value']

df['value'] = df['amount'] / val 

其中val是df['texts']

的数值

这是我的代码

val = df['texts'].str.extract('(\d+\.?\d*)', expand=False).astype(float)
df['value'] = df['amount']/val
print(df)

输出:

    texts                          amount     value
0   Sam is 5                       2000     400.000000
1   John is 3 years and 6 months   1200     400.000000
2   Jack is 4.5 years              7000     1555.555556
3   Shane is 25 years old          2000     80.000000

预期产出:

    texts                          amount     value
0   Sam is 5                       2000     400.000000
1   John is 3 years and 6 months   1200     342.85
2   Jack is 4.5 years              7000     1555.555556
3   Shane is 25 years old          2000     80.000000

上述代码中的问题是我无法弄清楚如何将3年6个月转换为3。5年。

其他信息:文字列仅包含年龄和月份的年龄值。

欢迎任何建议。感谢

1 个答案:

答案 0 :(得分:2)

我相信你需要:

注意:如果没有年份和月份文本,那么解决方案会计入多年

#extract all first numbers
a = df['texts'].str.extract('(\d+\.?\d*)', expand=False).astype(float)
#extract years only
b = df['texts'].str.extract('(\d+\.?\d*)\s+years', expand=False).astype(float)
#replace NaNs by a
y = b.combine_first(a)
print(y)
0     5.0
1     3.0
2     4.5
3    25.0
Name: texts, dtype: float64

#extract months only
m = df['texts'].str.extract('(\d+\.?\d*)\s+months', expand=False).astype(float) / 12
print (m)
0    NaN
1    0.5
2    NaN
3    NaN
Name: texts, dtype: float64

#add together
val = y.add(m, fill_value=0)
print (val)
0     5.0
1     3.5
2     4.5
3    25.0
Name: texts, dtype: float64
df['value'] = df['amount']/val
print (df)
                          texts  amount        value
0                      Sam is 5    2000   400.000000
1  John is 3 years and 6 months    1200   342.857143
2             Jack is 4.5 years    7000  1555.555556
3         Shane is 25 years old    2000    80.000000