Python matplot作图 横坐标修改了label，仍显示默认值 1.我想把1去掉，只显示我要的横坐标

Question

import numpy as np
import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif'] = 'simhei'
plt.rcParams['axes.unicode_minus'] = False
data_ = np.load('D:/学习/Python-数据分析/iris.npz',allow_pickle= True)
features_name = data_['features_name']
data = data_['data']
plt.figure(figsize=(20,20))
labels=[' sepal_length',' sepal_width','petal_length','petal_width','class']
plt.ylabel("长度")
for i in range(1,5):
    p = plt.subplot(1, 4, i)
    p.boxplot(data[:, i-1])
    plt.xlabel(labels[i-1])
    plt.ylabel('长度(cm)')
    plt.ylim(0, 8.0)

plt.show()