Question

我的数据框为：

df = pd.DataFrame({"id": [1,2,3,4,5],
                "text": ["This is a ratio of 13.4/10","Favorate rate of this id is 11/9","It may not be a good looking person. But he is vary popular (15/10)","Ratio is 12/10","very popular 17/10"],
                "name":["Joe","Adam","Sara","Jose","Bob"]})

我想将数字提取到两列中以得到以下结果：

df = pd.DataFrame({"id": [1,2,3,4,5],
                "text": ["This is a ratio of 13.4/10","Favorate rate of this id is 11/9","It may not be a good looking person. But he is vary popular (15/10)","Ratio is 12/10","very popular 17/10"],
                "name":["Joe","Adam","Sara","Jose","Bob"],
                "rating_nominator":[13.4,11,15,12,17],
                "rating_denominator":[10,9,10,10,10]})

感谢您的帮助。

Answer 1

您要匹配的常规模式是(some number)/(other number)。匹配浮点数不是一件容易的事，SO上有很多答案可以回答这个问题，因此您可以在这里使用它。

从this question改编而成的相当健壮的表达式是([+-]?(?:[0-9]*[.])?[0-9]+)。您可以将其与Series.str.extract和f字符串一起使用：

fpr = r'([+-]?(?:[0-9]*[.])?[0-9]+)'

res = df.text.str.extract(fr'{fpr}\/{fpr}').astype(float)

      0     1
0  13.4  10.0
1  11.0   9.0
2  15.0  10.0
3  12.0  10.0
4  17.0  10.0

要将其分配给您的DataFrame：

df[['rating_nominator', 'rating_denominator']] = res

   id                                               text  name  rating_nominator  rating_denominator
0   1                         This is a ratio of 13.4/10   Joe              13.4                10.0
1   2                   Favorate rate of this id is 11/9  Adam              11.0                 9.0
2   3  It may not be a good looking person. But he is...  Sara              15.0                10.0
3   4                                     Ratio is 12/10  Jose              12.0                10.0
4   5                                 very popular 17/10   Bob              17.0                10.0

Answer 2

您可以使用

df[['rating_nominator', 'rating_denominator']] = df['text'].str.extract('(-?\d+(?:\.\d+)?)/(-?\d+(?:\.\d+)?)').astype(float)

正则表达式(-?\d+(?:\.\d+)?)/(-?\d+(?:\.\d+)?)将捕获整数或浮点数作为分母或分母。

（编辑：this answer中的正则表达式涵盖了更多情况。我做出了一些假设，例如，您不会在数字中找到一元+符号。）

演示：

>>> df
   id                  text
0   1  foo 14.12/10.123 bar
1   2                 10/12
2   3             13.4/14.5
3   4          -12.24/-13.5
4   5                1/-1.2
>>>
>>> df[['rating_nominator', 'rating_denominator']] = df['text'].str.extract('(-?\d+(?:\.\d+)?)/(-?\d+(?:\.\d+)?)').astype(float)
>>> df
   id                  text  rating_nominator  rating_denominator
0   1  foo 14.12/10.123 bar               14.12            10.123
1   2                 10/12               10.00            12.000
2   3             13.4/14.5               13.40            14.500
3   4          -12.24/-13.5              -12.24           -13.500
4   5                1/-1.2                1.00            -1.20

从文本列中提取两列中的定量。

2 个答案: