reticulate lets you interface with Python from R. In Python, it is common to use (class) methods to interact with your variables. How do I access/execute the method of one Python variable in R when using reticulate? For example, if I create the following Python dictionary:
```{python}
fruits = {
"apple": 53,
"banana": None,
"melon": 7,
}
```
that is accessible using reticulate,
```{r}
py$fruits
```
## $apple
## [1] 53
##
## $banana
## NULL
##
## $melon
## [1] 7
How can I call one of the methods from the dictionary class, e.g. keys() from R?
```{python}
print(fruits.keys())
```
## dict_keys(['apple', 'banana', 'melon'])
I tried:
```{r error=TRUE}
py$fruits$keys()
```
## Error in eval(expr, envir, enclos): attempt to apply non-function
```{r error=TRUE}
py$fruits.keys()
```
## Error in py_get_attr_impl(x, name, silent): AttributeError: module '__main__' has no attribute 'fruits.keys'
but both tries failed.
As pointed out in Type Conversions, Python's dict objects become named lists in R. So, to access the equivalent of "dictionary keys" in R you would use names:
```{r}
names(py$fruits)
```
## [1] "melon" "apple" "banana"
You may choose to convert the result back to a dict-like object using reticulate::dict(). The resulting object would then function as you want:
```{r}
reticulate::dict( py$fruits )
```
## {'melon': 7, 'apple': 53, 'banana': None}
```{r}
reticulate::dict( py$fruits )$keys()
```
## ['melon', 'apple', 'banana']