无法将字符串转换为浮动：‘8,400,000,000

Question

我对机器学习很陌生，我坚持这个错误：

could not convert string to float: ' 8,400,000,000

我该怎么办？

import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.tree import DecisionTreeRegressor
from sklearn.metrics import mean_absolute_error
from sklearn import linear_model


df = pd.read_csv("housePrice.csv")

print(df.isna().sum())
print(df.head())
print(df.describe())

x = df[["Area","Room","Parking","Warehouse"]]
np.reshape(x , (3479, 4))
y = df.Price

print(x.shape)
print(y.shape)

print(df.info())

filler = df.fillna(method="ffill")
filler = df.fillna(method="bfill")



train_x, test_x, train_y, test_y = train_test_split(x , y ,random_state=0, test_size=0.3)
dt = DecisionTreeRegressor()


dt.fit(train_x , train_y)

pred_y = dt.predict(test_x)
print("MAE:" ,mean_absolute_error(test_y , pred_y))

Answer 1

根据错误消息：could not convert string to float: ' 8,400,000,000'，数据帧中的一个列有一个值' 8,400,000,000，它抛出错误，因为进入DecisionTree的所有数据都需要是数字的。需要首先将所有str类型数据转换为数字数据。

对于此错误消息中的特定值，需要删除' 8,400,000,000逗号,、前面的空格和撇号，以便使其成为可以转换为float类型的数字格式。

这样做的一种方法是：

df[COLUMN1] = df[COLUMN1].replace("'", '') # Replace apostrophe with empty string
df[COLUMN1] = df[COLUMN1].replace(",", '') # Relace comma with empty string
df[COLUMN1] = df[COLUMN1].replace(" ", '') # Replace whitespace with empty string
df[COLUMN1] = df[COLUMN1].astype(float) # Finally, convert column to float type

下面是另一个在熊猫专栏中替换这些字符的SO条目：replacing quotes, commas, apostrophes w/ regex - python/pandas