How to transform a string to a Class name in Python?

Question

I get a string selected_optimizer from HTML form

selected_optimizer = str(request.form['optimizer'])
print(selected_optimizer) #AdamOptimizer

I recall function

import tensorflow as tf

train_model(
    my_optimizer=tf.train.AdamOptimizer(learning_rate=0.05))

Is it possible to convert string as a Class name and get something like this:

train_model(
    my_optimizer=tf.train.selected_optimizer(learning_rate=0.05))

`dict` mapping or reflection, or [this](https://stackoverflow.com/questions/4030982/initialise-class-object-by-name) — David Zemens, Jun 13 '19 at 13:27

score 2 · Answer 1 · answered Jun 13 '19 at 13:24

2

Use a dictionary.

optimizers = {
    "AdamOptimizer": tf.train.AdamOptimizer,
    "OtherOptimizer": ....,
}
selected_optimizer = optimizers[request.form['optimizer']]
train_model(my_optimizer=selected_optimizer(learning_rate=0.05))

answered Jun 13 '19 at 13:24

Daniel Roseman

588,541
66
880
895

Jainil Patel · Answer 2 · 2019-06-13T13:34:13.120

1

import tensorflow as tf

selected_optimizer = str(request.form['optimizer'])
print(selected_optimizer) #AdamOptimizer

eval("train_model(my_optimizer=tf.train."+selected_optimizer+"(learning_rate=0.05))")

using eval is easier than this. according to me

def AdamOptimizer():
    print("hi")

strr="AdamOptimizer"

eval(strr+'()')

edited Jun 13 '19 at 13:34

answered Jun 13 '19 at 13:26

Jainil Patel

1,284
7
16

How to transform a string to a Class name in Python?

2 Answers2