我的代码行中出现以下错误，可能是什么原因？

Question

我的代码行：

import numpy as np
import pandas as pd
import seaborn as sns
from matplotlib import pyplot as plt

from statsmodels.tsa.api import ExpotentialSmoothing, SimpleExpSmoothing, Holt
from sklearn.linear_model import LinearRegression

import warnings
warnings.filter warnings('ignore')

df = pd.read_csv("monthly_csv.csv")
df.head()

** 警告：**

NameError                                 Traceback (most recent call last)
Cell In[4], line 1
----> `1 df = pd.read_csv("monthly_csv.csv")
      2 df.head()`

NameError: name 'pd' is not defined

我尝试运行代码，但它不起作用。我应该编辑什么才能让它工作？

Answer 1

import numpy as np
import pandas as pd
import seaborn as sns
from matplotlib import pyplot as plt

from statsmodels.tsa.api import ExpotentialSmoothing, SimpleExpSmoothing, Holt
from sklearn.linear_model import LinearRegression

import warnings
warnings.filterwarnings('ignore')

df = pd.read_csv("monthly_csv.csv")
df.head()

---

NameError                                 Traceback (most recent call last)
Cell In[46], line 1
----> 1 df = pd.read_csv("monthly_csv.csv")
      2 df.head()

NameError: name 'pd' is not defined

df.shape

---

NameError Traceback（最近一次调用最后一次） 单元格 In[47]，第 1 行 ----> 1 df.shape

名称错误：名称“df”未定义