Add a parameter to eval function that is applied to pd.df

Question

I have a program like below, it works fine when each function has only one parameter.

import pandas as pd

df = pd.DataFrame([1])
df.columns = ['number']

def add_one(x):
    return x+1

def add_two(x):
    return x+2

class Functions:
    add_one = "add_one"
    add_two = "add_two"

def main(df, func_name):
    return df.number.apply(eval(func_name))

func_name = Functions.add_one

main(df, func_name)

But I added another parameter to each function, it returned an error:

TypeError: 'int' object is not callable. 

How can I make it work with two parameters?

import pandas as pd

df = pd.DataFrame([1])
df.columns = ['number']


def add_one(x, a):
    return x+1+a

def add_two(x, a):
    return x+2+a

class Functions:
    add_one = "add_one"
    add_two = "add_two"

def main(df, func_name):
    a = 1
    return df.number.apply(eval(func_name + '(x, a)'))

func_name = Functions.add_one

main(df, func_name)

Answer 1

You can pass your arguments separately to the .apply function using the args parameter as shown below.

import pandas as pd

df = pd.DataFrame([1])
df.columns = ['number']


def add_one(x, a):
    return x+1+a

def add_two(x, a):
    return x+2+a

class Functions:
    add_one = "add_one"
    add_two = "add_two"

def main(df, func_name):
    a = 1
    return df.number.apply(eval(func_name), args=(a,))

func_name = Functions.add_one

main(df, func_name)

Output:

0    3
Name: number, dtype: int64