在 Pandas 中，如何检查三个组合字符串列是否 == 10 个字符，如果是，则插入到新列中？

Question

我想将三个 Pandas 字符串列组合成一个新列，如果新列的总组合字符数等于 10。

如果不等于 10，则检查下一个组合列。

如果 Phone1Area 等于 3 个字符串字符，Phone1Prefix 等于 3 个字符串字符，Phone1NumberPart 等于 4 个字符串字符，换句话说，总共十个字符，我尝试将这些列一起添加到一个新列中。如果它们是 3+3+4 个字符，我尝试添加列，df.loc，以及更多东西。

这是数据集的示例：

代码如下：

dfp['p1'] = df[(df['Phone1Area'].str.len() == 3.0)]['Phone1Area'] + 
df[(df['Phone1Exchange'].str.len() == 3.0)]['Phone1Exchange'] + 
df[(df['Phone1NumberPart'].str.len() == 4.0)]['Phone1NumberPart']


dfp['p2'] = df[(df['Phone2Area'].str.len() == 3.0)]['Phone2Area'] + 
df[(df['Phone2Exchange'].str.len() == 3.0)]['Phone2Exchange'] + 
df[(df['Phone2NumberPart'].str.len() == 4.0)]['Phone2NumberPart']

df_phone.loc[df_phone['p1'].str.len() == 10, 'phone'] = df_phone['p1']
df_phone.loc[df_phone['p2'].str.len() == 10, 'phone'] = df_phone['p2']

这是我想要它做的，但在 Pandas:

if df_phone['p1'].str.len() == 10:
    then insert df_phone['p1'] into df_phone['phone']
elif df_phone['p2'].str.len() == 10:
    then insert df_phone['p2'] into df_phone['phone']
elif df_phone['p3'].str.len() == 10:
    then insert df_phone['p3'] into df_phone['phone']

我希望 phone 列包含来自 phone 1 的 10 个字符，如果不是 10 个字符，那么 phone 列包含来自 phone 的 10 个字符phone2等

但其中一个结果是：

AttributeError: 'DataFrame' object has no attribute 'str'

知道如何解决这个问题吗？

Answer 1

这应该有帮助：

df['phone'] = ''
df['test_phone'] = df['phone1Area'] + df['phone1Exchange'] + df['phone1NumberPart']
df['phone'][df['test_phone'].str.len() == 10] = df['test_phone']
df['test_phone'] = df['phone2Area'] + df['phone2Exchange'] + df['phone2NumberPart']
df['phone'][(df['test_phone'].str.len() == 10) & (df['phone'] == '')] = df['test_phone']
df['test_phone'] = df['phone3Area'] + df['phone3Exchange'] + df['phone3NumberPart']
df['phone'][(df['test_phone'].str.len() == 10) & (df['phone'] == '')] = df['test_phone']
etc.

Answer 2

另一个使用 np.select 的解决方案应该更快：

conditions = [df_phone['p1'].str.len() == 10, df_phone['p2'].str.len() == 10,\
              df_phone['p3'].str.len() == 10]
choices = [df_phone['p1'], df_phone['p2'], df_phone['p3']]

df_phone['phone'] = np.select(conditions, choices, default = '')

Documentation:

np.select: pick the choice for the first True value encountered in conditions. If only False, fill with default.

在 Pandas 中，如何检查三个组合字符串列是否 == 10 个字符，如果是，则插入到新列中？

In Pandas, how do I check if three combined string columns == 10 characters, and if so, insert into new column?

python

string

substring

string-length

pandas