# Passing Parameter Values using a dictionary
**URL:** https://discourse.julialang.org/t/passing-parameter-values-using-a-dictionary/17117
**Category:** General Usage
**Tags:** question
**Created:** [November 3, 2018, 3:20pm UTC](https://discourse.julialang.org/t/passing-parameter-values-using-a-dictionary/17117 "2018-11-03T15:20:56Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Ajaychat3](https://discourse.julialang.org/u/Ajaychat3)
#### Post date: [November 3, 2018, 3:20pm UTC](https://discourse.julialang.org/t/passing-parameter-values-using-a-dictionary/17117/1 "2018-11-03T15:20:56Z")
I am trying to use a DecisionTree classifer and have specified the parameter value using a dicitonary. See below. An error is thrown when i try to do that
```julia
# build a classifier
dtclf = DecisionTree.DecisionTreeClassifier()
# run randomized search
nfold=5
dt_search = RandomizedSearchCV(dtclf, param_grid, n_iter=n_iters,cv=nfold, scoring=scorer,
random_state=MersenneTwister(123));
DecisionTree.fit!(dt_search, X_train0, y_train0)
dict=dt_search.best_params_
model=DecisionTreeClassifier(dict)
MethodError: no method matching DecisionTreeClassifier(::Dict{Symbol,Any})
Closest candidates are:
DecisionTreeClassifier(; pruning_purity_threshold, max_depth, min_samples_leaf, min_samples_split, min_purity_increase, n_subfeatures, rng, root, classes) at C:\Users\chatura\.julia\packages\DecisionTree\wpdwP\src\scikitlearnAPI.jl:42
Stacktrace:
[1] top-level scope at In[152]:1
```
---
### Author:  [@Ajaychat3](https://discourse.julialang.org/u/Ajaychat3)
#### Post date: [November 3, 2018, 3:41pm UTC](https://discourse.julialang.org/t/passing-parameter-values-using-a-dictionary/17117/2 "2018-11-03T15:41:04Z")
I could serach the approach on web. It work likes this.
```julia
model2=DecisionTreeClassifier(;dict...)
```