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Using functions defined in primitive modules
(1 answer)
no function or associated item named `from_str` found for type `hyper::mime::Mime`
(1 answer)
How to create an `IpAddr` without knowing the specific IP version?
(1 answer)
Closed 3 years ago.
I'm trying to use the Cidr crate, and need to convert strings to CIDRs. But it's not working and I can't figure out why. I think I need to use something, but std::str::FromStr doesn't help. What's worse is that I don't even know where to look next.
error[E0599]: no variant named `from_string` found for type `cidr::AnyIpCidr` in the current scope
--> src/main.rs:45:30
|
45 | let c = cidr::AnyIpCidr::from_string(ipstr);
| -----------------^^^^^^^^^^^
| |
| variant not found in `cidr::AnyIpCidr`
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How to create a formatted String out of a literal in Rust?
(2 answers)
Closed 4 months ago.
Is there a way to use String::from with variables? I tried using it similarly to println!(), but doesn't seem to work.
String::from("[INFO]: {}", message)
Expected:
// Returns: "[INFO]: My info message here"
Got:
// Error: argument unexpected
Rust doesn’t really practice variadic functions because we have big metaprogramming potential: modern generic system and about 6 types of macros.
In this case you need the format macro:
format!("[INFO]: {}", message)
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crate name with hyphens not being recognized
(2 answers)
Why is changing hyphenated crate names to underscored names possible and what are the rules for naming under such ambiguous scenarios?
(1 answer)
Closed 1 year ago.
This crate's name is:
name = "rtsp-types"
How can I use it on my project?
I added to the Cargo.toml:
[dependencies]
rtsp-types = { path = "../rtsp-types" }
however I can't do
use rtsp-types
because of the - symbol.
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Finding the source code for built-in Python functions?
(8 answers)
Closed 3 years ago.
Where can I find the source code for the implementation of object.__new__. It shows as "built-in". I would like to see how it works.
>>> object.__new__
<built-in method __new__ of type object at 0x822060>
Python3's object.__new__ is internal (built-in). It's not written in Python. You can find the C code for it as object_new(PyTypeObject *type, PyObject *args, PyObject *kwds) in typeobject.c.
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What does "list comprehension" and similar mean? How does it work and how can I use it?
(5 answers)
Closed 3 years ago.
I have scoured the internet and I cannot find any reference to this type of for loop:
variable = [(item["attribute1"], item["attribute2]") for item in piece_of_json_data]
I am using this to update wtform's SelecField choices:
form.SelectField.choices = variable
but I can only get it to work if I replace one of the attributes in parenthesis with a static number:
variable = [(1, item["attribute2"]) for item in piece_of_json_data]
but that sets the value of the option field to "1", when I need the option values to be one of the attributes as a string.
Does this create a dict? a tuple? is there some kind of terminology for this that I can use to find documentation?
Thanks to the comments, I now understand that I am using list comprehension to create a tuple. The tuple works fine with both string and integer values. My issue has to do with .choices not accepting a string.
I found that my only problem is that I had coerce set to int on my selectfield, so naturally it wanted an integer.
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Get the type of a variable in VBScript
(6 answers)
Closed 7 years ago.
I am passing one object to function which needs to take action according to object type. e.g. If object is of "Scripting.Dictionary" then count keys and if it is "Scripting.FileSystemObject" then close it.
In short as like typeof in c# and variableName.class in java, how we can find which scripting object we are using ?
Use the TypeName function to get the type of a variable.
TypeName Function
Returns a string that provides Variant subtype information about a variable.
TypeName(varname)