Type Nothing has no field match

General Usage
1

I’m learning Linear Regression model with housing dataset from Kaggle.

Dealing with a problem to extract int or float from string make me some confusing.

# rename columns
renamed_df = rename(df2, Dict("Diện tích" => "Area", "Giá/m2" => "Price/m2"))
# convert "," => "." in string
comma_to_dot_column = map(x -> replace(x, "," => "."), renamed_df[:, "Price/m2"])
# extract int or float from string
for i in comma_to_dot_column
    @show typeof(match(r"[+-]?\d+(\.\d+)?", i).match)
end

The for loop returns error: type Nothing has no field match despite the fact that all regex match in the column existing in RegexMatch datatype.

image
image1059×905 143 KB

I migrate from Python to Julia so maybe missing some important concept about Julia Datatype in this code

2

in this line, the .match would throw an error before you can show anything, so I suggest you do this:

m = match(r"[+-]?\d+(\.\d+)?", i)
if isnothing(m)
    @show i
end
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