one of the things I really miss about langauges like python is that you don't have to clutter your import space in order to use most functionality.

That is not true with rust.

In rust, I frequently find myself writing dev_prefix files to import structs and traits that are necessary in practically every application.

Here is an example of a possible one for stdlibx:

//! `import stdlibx::prefix::*` so you can be ready to code!
// traits
pub use std::ascii::AsciiExt; // to_ascii_uppercase(), etc
pub use std::clone::Clone;
pub use std::convert::AsRef;
pub use std::default::Default;
pub use std::fmt::{Debug, Write as FmtWrite};
pub use std::io::{Read, Seek, SeekFrom, Write};
pub use std::iter::{FromIterator, Iterator};
pub use std::str::FromStr;
pub use std::ops::{Deref, DerefMut};
// structs
pub use std::collections::{HashMap, HashSet, VecDeque};
pub use std::ffi::OsString;
pub use std::path::{Path, PathBuf};
pub use std::rc::Rc;
pub use std::sync::Arc;

This list was basically put together because of the number of times I write a line of code and then hit compile and see that it doesn't work because of a forgotten import. It is quite annoying to not have access (by default) to std functions like from_iterator or write_str because you forgot to import a trait! It is almost as frustrating to be using a HashMap and realize it isn't defined. This is especially frustrating for newbies, so I see this lib as a possible (and effective) workaround.