Python Global Variables - Not Defined?

Question

I\'m running into an issue where a global variable isn\'t \"remembered\" after it\'s modified in 2 different functions. The variable df is supposed to be a data

Answer 1

You have to use the global keyword inside the function rather than outside. All the df that you have defined inside your function are locally scoped. Here is the right way -

df = pd.DataFrame() # No need to use global here

def __init__(self, master):
    global df # declare here
    df = None
....

def load(self):
    global df # declare here
    ....
    df = pd.read_csv(filepath)

def save(self):
    global df # declare here
    ....
    df = df.append(...)