python - 未知的字符问题�

Question

我已将一个数据框读入Python，其列名包含欧元符号“price_€。Python 将该列视为price_�。它不允许我使用 € 或 � 引用该列

File "<ipython-input-53-d7f8249147e7>", line 1
df[price_€] = df[0].str.replace(r'[€,]', '').astype('float')
         ^
SyntaxError: invalid syntax

有什么想法如何从列名称中删除它，以便我可以开始引用它吗？

Answer 1

您不能在变量名称中使用欧元符号:

Identifiers (also referred to as names) are described by the following lexical definitions:

identifier ::=  (letter|"_") (letter | digit | "_")*
letter     ::=  lowercase | uppercase
lowercase  ::=  "a"..."z"
uppercase  ::=  "A"..."Z"
digit      ::=  "0"..."9"

您需要使用字符串:

df["price_€"] ...

pandas 实际上对我来说欧元符号没有问题:

import pandas as pd

df = pd.DataFrame([[1, 2]], columns=["£", "€"])

print(df["€"])
print(df["£"])
0    2
Name: €, dtype: int64
0    1
Name: £, dtype: int64

该文件采用 cp1252 编码，因此您需要指定编码:

mport pandas as pd
iimport codecs
df = pd.read_csv("PPR-2015.csv",header=0,encoding="cp1252")

print(df.columns)
Index([u'Date of Sale (dd/mm/yyyy)', u'Address', u'Postal Code', u'County', 
u'Price (€)', u'Not Full Market Price', u'VAT Exclusive', u'Description of Property', u'Property Size Description'], dtype='object')

print(df[u'Price (€)'])
0     €138,000.00
1     €270,000.00
2      €67,000.00
3     €900,000.00
4     €176,000.00
5     €155,000.00
6     €100,000.00
7     €120,000.00
8     €470,000.00
9     €140,000.00
10    €592,000.00
11     €85,000.00
12    €422,500.00
13    €225,000.00
14     €55,000.00
...
17433    €262,000.00
17434    €155,000.00
17435    €750,000.00
17436     €96,291.69
17437    €112,000.00
17438    €350,000.00
17439    €190,000.00
17440     €25,000.00
17441    €100,000.00
17442     €75,000.00
17443     €46,000.00
17444    €175,000.00
17445     €48,500.00
17446    €150,000.00
17447    €400,000.00
Name: Price (€), Length: 17448, dtype: object

然后更改为 float :

df[u'Price (€)'] = df[u'Price (€)'].str.replace(ur'[€,]'), '').astype('float')

print(df['Price (€)'.decode("utf-8")])

输出:

0     138000
1     270000
2      67000
3     900000
4     176000
5     155000
6     100000
7     120000
8     470000
9     140000
10    592000
11     85000
12    422500
13    225000
14     55000
...
17433    262000.00
17434    155000.00
17435    750000.00
17436     96291.69
17437    112000.00
17438    350000.00
17439    190000.00
17440     25000.00
17441    100000.00
17442     75000.00
17443     46000.00
17444    175000.00
17445     48500.00
17446    150000.00
17447    400000.00
Name: Price (€), Length: 17448, dtype: float64