使用Jupyter Notebook出现语法错误，求原因分析（附相关代码）

Hey there! Let's break down the syntax error in your code and fix it step by step.

核心错误原因 #

The immediate syntax error comes from the last line of your code:

print accidents.mean()

This is Python 2 syntax, but Jupyter Notebook almost always runs on Python 3 by default. In Python 3, print is a built-in function, so you must wrap its argument in parentheses. Missing these parentheses will throw a SyntaxError.

修正后的完整代码 #

Here's your revised code with the syntax fix plus some minor improvements for readability and robustness:

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

# Load the accident data
data = pd.read_csv("files/ch04/ACCIDENTS_GU_BCN_2013.csv", encoding='unicode_escape')

# Create combined date string and convert to datetime
data['Date'] = data[u'Dia de mes'].astype(str) + '-' + data[u'Mes de any'].astype(str)
# Specify the date format to avoid parsing ambiguities
data['Date'] = pd.to_datetime(data['Date'], format='%d-%m')

# Group by date and count accidents per day
accidents = data.groupby(['Date']).size()

# Fixed print statement (Python 3 compatible)
print(accidents.mean())

额外优化说明 #

• Replaced apply(lambda x: str(x)) with astype(str): This is a more efficient and concise way to convert column values to strings in pandas.
• Added format='%d-%m' to pd.to_datetime: Explicitly defining the date format ensures pandas parses your day-month strings correctly, even if your system's default date format differs.

内容的提问来源于stack exchange，提问作者Çağlar Seviç