Python 为什么用箱线图不能正确显示胡须

我想为具有百分比的数据框的列绘制一个箱线图，并设置

import random
from random import randint

import matplotlib.pyplot as plt
import pandas as pd

random.seed(42)
lst=[]
for x in range(140):
    x=randint(1,100)
    lst.append(x)
lst.append(-1)
lst.append(300)
lst.append(140)
print(lst)

df = pd.DataFrame({0:lst})

这是我的功能:

def boxplot(df,var,lower_limit=None,upper_limit=None):
    
    q1=df[var].quantile(0.25)
    q3=df[var].quantile(0.75)
    iqr=q3-q1
    w1=w2=1.5
    
    if (q1!=q3) and (lower_limit!=None):
        w1=(q1-lower_limit)/iqr
    
    if (q1!=q3) and (upper_limit!=None):
        w2=(upper_limit-q3)/iqr
    
    plt.figure(figsize=(5,5))
    df.boxplot(column=var,whis=(w1,w2))
    plt.show()
    
    print(f'The minimum of {var} is',df[var].min(),'and its maximum is ',df[var].max(),"\n")
    print(f'The first quantile of {var} is ',q1,'its median is ',df[var].median(),'and its third quantile is ',q3,"\n")

I coded boxplot(df,0,lower_limit=0,upper_limit=100) and I had this result:

但是胡须没有达到100，我想知道为什么.