报错 name 'ticker' is not defined

抱歉，我的错误。在使用`ticker`模块之前，需要先导入该模块。请将代码修改如下：

import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.ticker as ticker  # 导入ticker模块

# 读取数据文件
data = pd.read_csv('temperature.csv', parse_dates=['日期'])

# 将日期列转换为年份列
data['年份'] = pd.DatetimeIndex(data['日期']).year

# 计算每年的平均气温
yearly_temp = data.groupby('年份')['平均气温'].mean()

# 绘制线性图
plt.plot(yearly_temp.index, yearly_temp.values)
plt.title('2000年到2019年广州年平均气温')
plt.xlabel('年份')
plt.ylabel('平均气温')

# 设置X轴刻度显示整数
plt.gca().xaxis.set_major_locator(ticker.MaxNLocator(integer=True))

plt.show()

这样，就可以成功导入`ticker`模块并使用其中的`MaxNLocator`函数了。

相关问题

name 'MultipleLocator' is not defined

这个错误是因为在代码中没有正确导入`MultipleLocator`类。你需要在代码的开头添加以下导入语句:

from matplotlib.ticker import MultipleLocator

这样就可以正确使用`MultipleLocator`类了。
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NameError: name 'mtick' is not defined

The error message "NameError: name 'mtick' is not defined" indicates that the module "mtick" has not been imported, or it has not been imported correctly.

To fix this error, you need to import the "mtick" module using the following code:

import matplotlib.ticker as mtick

This will import the "mtick" module from the "matplotlib.ticker" package, which provides classes and functions for formatting tick labels in plots created with Matplotlib. Once you have imported the module, you can use its functions and classes in your code without encountering the "NameError" again.