Hi Python users of Stan,

I find this library quite useful so I thought I’d share it:

It caches Stan MCMC for quicker model iterations and enhanced productivity. It does this by wrapping CmdStanPy and recognises near-identical (comments or white space changes only) code or data, in which case a cached result is returned.

**Usage**:

```
model = """
data {
int N;
}
parameters {
real<lower=-10.0, upper=10.0> x[N];
}
model {
for (i in 1:N-1) {
target += -2 * (100 * square(x[i+1] - square(x[i])) + square(1 - x[i]));
}
}
"""
data = dict(N=2)
import cmdstancache
stan_variables, method_variables = cmdstancache.run_stan(
model,
data=data,
# any other CmdStanMCMC.sample() parameters go here
seed=42
)
```

**Now comes the trick:**

- If you run this code twice, the second time the stored result is read.
- If you add or modify a code comment, the same result is returned without having to resample.

More technical details here: cmdstancache · PyPI