Question

我有一列电话号码（作为字符串）。然后还有另一列给我零的数量（如int），我想附加到现有的电话号码。我想做的是像（5 *“0”=＆gt;“00000”）。还有一个先决条件。如果电话号码以“1”结尾，则只能添加零。

Example:
>>> df = pd.DataFrame([["11", 2], ["21", 3], ["10", 6]], columns=['phone', 'ext_length'])

What I tried:
>>> df.loc[(df.phone.str.endswith("1")), "complete_phone"] = df.phone + (df.ext_length * "0")

在过滤手机结束于“1”并且创建“complete_phone”列的正确行时，我无法使“数学”工作。我正在

TypeError: ufunc 'multiply' did not contain a loop with signature matching types dtype('<U21') dtype('<U21') dtype('<U21')

我也不理解错误信息，也不知道如何解决这个问题。

PS：我也在寻找一个链接，它显示了如何正确包含python示例，正如我在[in：]和[out：]加上结果的其他问题中看到的那样。任何提示？

Answer 1

如果条件为True，我认为您需要mask替换 str.repeat：

s = pd.Series(['0'], index=df.index)
mask = df.phone.str.endswith("1")
df["complete_phone"] = df.phone.mask(mask, df.phone + s.str.repeat(df.ext_length))
print (df)
  phone  ext_length complete_phone
0    11           2           1100
1    21           3          21000
2    10           6             10

DataFrame.apply的另一个解决方案：

mask = df.phone.str.endswith("1")
df["complete_phone"] = df['phone'].mask(mask, df.apply(lambda x: x['phone'] + 
                                                                 '0' * x.ext_length, axis=1))
print (df)
  phone  ext_length complete_phone
0    11           2           1100
1    21           3          21000
2    10           6             10

mask = df.phone.str.endswith("1")
df["complete_phone"] = df.phone.mask(mask, df['phone'] +
                                           df['ext_length'].apply(lambda x:'0'*x))
print (df)
  phone  ext_length complete_phone
0    11           2           1100
1    21           3          21000
2    10           6             10

如果掩码为NaN，则您的解决方案类似于False：

mask = df.phone.str.endswith("1")
df.loc[mask, "complete_phone"] = df['phone'] + df.apply(lambda x: '0' * x.ext_length, axis=1)
  phone  ext_length complete_phone
0    11           2           1100
1    21           3          21000
2    10           6            NaN

Answer 2

In [1]: import pandas as pd

In [2]: df = pd.DataFrame([["11", 2], ["21", 3], ["10", 6]], columns=['phone', 'ext_length'])

In [3]: df
Out[3]: 
  phone  ext_length
0    11           2
1    21           3
2    10           6

In [4]: df['complete_phone'] = [number+'0'*length if number.endswith('1') else number for number, length in zip(df.phone, df.ext_length)]

In [5]: df
Out[5]: 
  phone  ext_length complete_phone
0    11           2           1100
1    21           3          21000
2    10           6             10

Answer 3

我认为ostream &operator<<(ostream &out, const BigInteger &t)功能派上用场了：

apply

根据另一列中设置的数量，将“零”添加到pandas列

3 个答案: