Julia：删除DataFrame中名称以数字开头的列报错及解决方法

Let's break down why you're hitting that UndefVarError: SsnPorchH not defined error first:

When you write :3SsnPorchH in Julia, the language doesn't interpret this as a single symbol representing your column name. Instead, it parses it as the expression 3 * SsnPorchH—treating 3 as a number and SsnPorchH as an undefined variable, hence the error.

Luckily, there are a few straightforward ways to fix this and delete your target column correctly:

Method 1: Use a quoted symbol literal #

Wrap the column name in double quotes immediately after the colon to force Julia to recognize it as a single symbol:

delete!(features, [:"3SsnPorchH"])

Method 2: Explicitly create a Symbol from a string #

If you prefer working with strings (especially useful if your column name is generated dynamically), convert the string to a Symbol first:

target_col = Symbol("3SsnPorchH")
delete!(features, [target_col])

Method 3: Use the column name as a string (DataFrames v1.0+) #

Starting with DataFrames version 1.0, most column-manipulation functions accept string inputs directly. This is often the simplest approach for special-named columns:

delete!(features, ["3SsnPorchH"])

All three methods will correctly target your 3SsnPorchH column without triggering parsing errors. This trick works for any column name with special characters, spaces, or leading numbers—just remember to avoid raw symbol literals for those cases!

内容的提问来源于stack exchange，提问作者tktktk0711