How do I loop through a list and find the index of a common element in another list?-CodePudding

I have a long list of Tickers and Weights that look something like this.

SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]

I also have a list of screened stock tickers.

portfolio = ['MSFT', 'GOOGL', 'GOOG']

I need to get the index's of the portfolio stocks in the SP500 list and then use that to get their corresponding weight, which I then want to put in a dataframe.

I'm to create the dataframe by having 3 lists: index's, portfolio (stock name), weight.

This is how I plan on doing that:

I'm struggling with actually putting these lists together. Now I can get the required information of individual stocks manually like...

x = input('stock from portfolio:')
index = SP500.index('x')

print(index)        #index
print(x)            #ticker name
print(W500[index])  #weight 

#For input MSFT
>> 0
>> MSFT
>> 6

I'm struggling with doing this for each stock in the list "portfolio" and putting all of the results into the three lists. I get that I have to loop through the "portfolio" list and basically do what I've just shown you, but I can't put all the steps together.

Does anyone have any tips as to how I could go about coding this? (and maybe also briefly explain the logic behind any potential solutions you have in mind).

CodePudding user response：

You can use list.index("item") to get the index of a specific item

example:

SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]

weight = 0
index = SP500.index("MSFT")
print(weight500(index))
>> 6

CodePudding user response：

You can use a dictionary:

SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]
weights = {ticker: weight for ticker, weight in zip(SP500, weight)}

# If your ticker is 'GOOGL'
w = weights['GOOGL']  # w == 2.1

CodePudding user response：

something like this?:

SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]
SP_wight_dict = dict(zip(SP500, weight500))
portfolio = ['MSFT', 'GOOGL', 'GOOG']

for i in portfolio:
    print(f"Weight = {SP_wight_dict[i]}, Index = {SP500.index(i)}")

CodePudding user response：

Instead of manually doing you can use a loop.


SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]

x = input('stock from portfolio:')

combined_lst = zip(SP500,weight500)

for i, info in enumerate(combined_lst):
    if info[0] == x:
        print(i)
        print(x)
        print(info[1])
        break

OUTPUT

stock from portfolio:MSFT
0
MSFT
6

AND

Instead of manually putting index and weight and then converting it in a DataFrame you can do this.

import pandas as pd
SP500 = ['MSFT', 'AAPL', 'AMZN', 'TSLA', 'GOOGL', 'GOOG', 'FB']
weight500 = [6, 5.9, 3, 2.5, 2.3, 2.1, 2]

portfolio = ['MSFT', 'GOOGL', 'GOOG']


lst = []

for a in portfolio:
    index = SP500.index(a)
    weight = weight500[index]
    lst.append([index,a,weight])
df = pd.DataFrame(lst)
print(df)

OUTPUT