数据可视化问题，为什么一直报错

Question

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

Data = pd.read_csv('fangjia2023_清洗.csv',sep=',')
plt.figure(figsize=(12,8))
ax = plt.axes()
ax.set_facecolor("lavender")#背景色
plt.rcParams['font.sans-serif']=['SimHei']
x=Data['城市']
y=Data['房价']
plt.scatter(x,y,c='mediumpurple')
z = np.polyfit(x, y, 1)#numpy线性拟合
p = np.poly1d(z)#多项式
plt.plot(x,p(x),color='rebeccapurple',linestyle="--")#线的格式
print("y=%.6fx+(%.6f)"%(z[0],z[1]))#打印拟合式
plt.grid()  # 显示网格线
plt.xlabel("城市名称",size=15)
plt.ylabel("房子价格",size=15)
plt.title("房价排名与城市发展的关系",size=15)
plt.show()



    z = np.polyfit(x, y, 1)#numpy线性拟合
  File "<__array_function__ internals>", line 180, in polyfit
  File "D:\python3.6.2\lib\site-packages\numpy\lib\polynomial.py", line 629, in polyfit
    x = NX.asarray(x) + 0.0
TypeError: can only concatenate str (not "float") to str

为什么报错啊?

Answer 1

先转换下，字符串和数字没法直接连接