您需要将修剪后的列分配回原始列，而不是进行子集设置，并且 str.replace 方法似乎没有 to_replace 和 value 参数。而是使用 pat 和 repl 参数：

You need to assign the trimmed column back to the original column instead of doing subsetting, and also the str.replace method doesn't seem to have the to_replace and value parameter. It has pat and repl parameter instead:

df["Date"] = df["Date"].str.replace("\s:00", "")

df
#   ID       Date
#0   1  8/24/1995
#1   2   8/1/1899