the HTML form encoding is ambiguous as to whether an argument is a single value or a list with one element, RequestHandler has distinct methods to allow the application to indicate whether or not it expects are available in self.request.files, which maps names (the name of the HTML element) to a list of files. Each file is a dictionary of the form {"filename":..., "content_type":..., "body": pass include_host as a keyword argument. RequestHandler.xsrf_form_html() → str An HTML element to be included with all POST forms. It defines the _xsrf input value, which we check on all POST

arguments and will be passed to the handler’s HTTP method. If a dictionary is passed as the third element of the URLSpec, it supplies the initialization arguments which will be passed to RequestHandler.initialize the HTML form encoding is ambiguous as to whether an argument is a single value or a list with one element, RequestHandler has distinct methods to allow the application to indicate whether or not it expects are available in self.request.files, which maps names (the name of the HTML element) to a list of files. Each file is a dictionary of the form {"filename":..., "content_type":..., "body":

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does change the first element 42 julia> a = 3.14159 # a is now the name of a different object 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: 42 numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does change the first element 42 julia> a = 3.14159 # a is now the name of a different object 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: 42 numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does change the first element 42 julia> a = 3.14159 # a is now the name of a different object 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: 42 numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does change the first element 42 julia> a = 3.14159 # a is now the name of a different object 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: 42 numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does change the first element 42 julia> a = 3.14159 # a is now the name of a different object 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: 42 numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does first element 42 julia> a = 3.14159 # a is now the name of a different objectCHAPTER 4. VARIABLES 14 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does first element 42 julia> a = 3.14159 # a is now the name of a different objectCHAPTER 4. VARIABLES 14 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction

changed: julia> a = [1,2,3] # an array of 3 integers 3-element Vector{Int64}: 1 2 3 julia> b = a # both b and a are names for the same array! 3-element Vector{Int64}: 1 2 3 Here, the line b = a does first element 42 julia> a = 3.14159 # a is now the name of a different objectCHAPTER 4. VARIABLES 14 3.14159 julia> b # b refers to the original array object, which has been mutated 3-element Vector{Int64}: numeric types: Expression Name Description +x unary plus the identity operation -x unary minus maps values to their additive inverses x + y binary plus performs addition x - y binary minus performs subtraction