Invalid syntax with an f-string

[Mark17]

I'm getting invalid syntax with Python showing a carrot under the first colon. What did I do wrong?

                    print({}, ",", {}, ",", {}, ",", {}, ",", {}, ",", {}, ",", {:.2f}, ",", {:.2f}, ",", {:.2f}, ",", {}, ",",
                        {:.2f}, ",", {}, ",", {}, ",", {}, ",", {}, ",", {}, ",", {:.2f}, ",", {:.2f}, ",", {}, ",", {:.2f},
                        ",", {:.2f}, ",", {:.2f}, ",", {:.2f}.format(spread_count, date, trade_date, L_spx, L_strike, L_price,
                        L_iv, L_delta, L_theta, S_price, S_iv, L_exp_mo, L_dte_trade_inception, S_exp_mo, S_dte_trade_inception,
                        spread_width, S_delta, S_theta, P_price, P_delta, P_theta, P_t_d, P_skew), file=strike_file) #testing f-string formatting

[deanhystad]

That is not f-string formatting, that is the format() command and it is really, really wrong.

f-string looks like this:

count = 1
price = 1.2
name = "My name"
print(f"{count}, {name}, {price:.2f}")

[Mark17]

That is not f-string formatting, that is the format() command and it is really, really wrong.

f-string looks like this:

count = 1
price = 1.2
name = "My name"
print(f"{count}, {name}, {price:.2f}")

My mistake... I had that confused.

In any case, what's wrong with the syntax in my usage of the format command here? Note: the output is to a .csv file with over 20 columns, which is why I have all the ",", and such.

[snippsat]

In any case, what's wrong with the syntax in my usage of the format command here?

Almost all of it is wrong,learn to test smaller part before writing so much.

To give some example how it can be done

import csv

with open('birthday.csv') as csv_file:
    reader = csv.reader(csv_file, delimiter=',')
    for row in reader:
        print('{:<15}  {:<15}  {:<15}'.format(*row))

Output:
name             department       birthday month 
John Smith       Accounting       November       
Erica Meyers     IT               March 

Pandas and tabulate

from tabulate import tabulate
import pandas as pd

df = pd.read_csv('birthday.csv')
print(tabulate(df, headers='keys', tablefmt='psql', showindex=False))

Output:
+--------------+--------------+------------------+
| name         | department   | birthday month   |
|--------------+--------------+------------------|
| John Smith   | Accounting   | November         |
| Erica Meyers | IT           | March            |
+--------------+--------------+------------------+

CSV file used:

Output:
name,department,birthday month
John Smith,Accounting,November
Erica Meyers,IT,March

[BashBedlam]

It looks like this is what you're looking for:

spread_count = 27.24583
date = 'Jan 13 2022'
trade_date = 'yesterday'
L_spx = 144
L_strike = 'None'
print ('{0:.2f},{1},{2},{3}'.format(spread_count, date, trade_date, L_spx, L_strike))

Output:
27.25,Jan 13 2022,yesterday,144

[Mark17]

It looks like this is what you're looking for:

spread_count = 27.24583
date = 'Jan 13 2022'
trade_date = 'yesterday'
L_spx = 144
L_strike = 'None'
print ('{0:.2f},{1},{2},{3}'.format(spread_count, date, trade_date, L_spx, L_strike))

Output:
27.25,Jan 13 2022,yesterday,144

Nice... looks like it works without the numbers too and I don't need all those extra commas in quotes to get the values into separate cells. Thanks!

[snippsat]

With f-string that preferable and modern way to use now,it would be like.

spread_count = 27.24583
date = 'Jan 13 2022'
trade_date = 'yesterday'
L_spx = 144
L_strike = 'None'
print (f'{spread_count:.2f},{date},{trade_date},{L_strike}')

Output:
27.25,Jan 13 2022,yesterday,None

Python 3's f-Strings: An Improved String Formatting Syntax (Guide)

[Mark17]

With f-string that preferable and modern way to use now,it would be like.

spread_count = 27.24583
date = 'Jan 13 2022'
trade_date = 'yesterday'
L_spx = 144
L_strike = 'None'
print (f'{spread_count:.2f},{date},{trade_date},{L_strike}')

Output:
27.25,Jan 13 2022,yesterday,None

Python 3's f-Strings: An Improved String Formatting Syntax (Guide)

I'll try to start using f-strings and getting used to this. Thanks!