Python: Save variables-names and use them later in a loop

I downloaded DataFrames (depending on how many assets are in the variable “assets”) and created for each one its own variable by using globals().

Now, I require a loop to pick up each created variable, to perform other tasks with these variables.

Before this, I need to “save” the created variables, maybe in some kind of dictionary?

start = "2019-01-01"
end = "2020-01-01"
assets = ["FB" , "AMZN" , "AAPL" , "NFLX" , "GOOG"]

i = 0
while (i < len(assets)):
    try:
        globals()["Stock_%s" %assets[i]] = pd.DataFrame(web.DataReader(assets[i] , "yahoo" , start , end))
        i += 1     
    except: 
        break
        print("Error")

The created DataFrames are called:

Stock_FB
Stock_AMZN
etc..

Any help would be appreciated.

Answer

Creating variables by assigning to globals() is not only unnecessarily difficult in itself, it makes iterating over the result afterward also unnecessarily difficult. Avoid it altogether; instead of:

i = 0
while (i < len(assets)):
    try:
        globals()["Stock_%s" %assets[i]] = pd.DataFrame(web.DataReader(assets[i] , "yahoo" , start , end))
        i += 1     
    except: 
        break
        print("Error")

do:

stocks = {
    asset: pd.DataFrame(web.DataReader(asset, "yahoo", start, end))
    for asset in assets
}

Now if you want to do something with each of the dataframes you’ve created you can do:

for stock_data in stocks.values():
    # do something with 'stock_data'

If you need to do something with the symbol (FB, etc) do:

for symbol, stock_data in stocks.items():
    # do something with 'symbol' and 'stock_data'