Class: Polars::Schema

Inherits:
Object
  • Object
show all
Defined in:
lib/polars/schema.rb

Instance Method Summary collapse

Constructor Details

#initialize(schema = nil, check_dtypes: true) ⇒ Schema

Ordered mapping of column names to their data type.



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# File 'lib/polars/schema.rb', line 8

def initialize(schema = nil, check_dtypes: true)
  input = schema || {}
  @schema = {}
  input.each do |name, tp|
    if !check_dtypes
      @schema[name] = tp
    elsif Utils.is_polars_dtype(tp)
      @schema[name] = _check_dtype(tp)
    else
      self[name] = tp
    end
  end
end

Instance Method Details

#[](key) ⇒ Object

Returns the data type of the column.



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# File 'lib/polars/schema.rb', line 25

def [](key)
  @schema[key]
end

#[]=(name, dtype) ⇒ Object

Sets the data type of the column.



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# File 'lib/polars/schema.rb', line 32

def []=(name, dtype)
  _check_dtype(dtype)
  @schema[name] = dtype
end

#dtypes ⇒ Array

Get the data types of the schema.

Examples:

s = Polars::Schema.new({"x" => Polars::UInt8.new, "y" => Polars::List.new(Polars::UInt8)})
s.dtypes
# => [Polars::UInt8, Polars::List(Polars::UInt8)]



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# File 'lib/polars/schema.rb', line 57

def dtypes
  @schema.values
end

#length ⇒ Integer

Get the number of schema entries.

Examples:

s = Polars::Schema.new({"x" => Polars::Int32.new, "y" => Polars::List.new(Polars::String)})
s.length
# => 2



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# File 'lib/polars/schema.rb', line 69

def length
  @schema.length
end

#names ⇒ Array

Get the column names of the schema.

Examples:

s = Polars::Schema.new({"x" => Polars::Float64.new, "y" => Polars::Datetime.new(time_zone: "UTC")})
s.names
# => ["x", "y"]



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# File 'lib/polars/schema.rb', line 45

def names
  @schema.keys
end

#to_s ⇒ String Also known as: inspect

Returns a string representing the Schema.



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# File 'lib/polars/schema.rb', line 76

def to_s
  "#{self.class.name}(#{@schema})"
end