What do you anticipate would be included in the contract as consequences for it being broken? They would have to be agreed upon by both parties, and I can't imagine a company agreeing to punitive measures.

Where do you plan to find a company not using Excel, or any spreadsheet application?

@Steve, I have already done so, & I do not expect that to change.

@Oso, I don't want to include punitive measures or anything like that, I would like to just able to refuse to use it in case they ask me to.

@virolino, I am ok with SQL or similar. Yes, I might not be able to find such a company.

Just for completeness, are you talking about your contract of employment, or are you thinking of working for this putative company as a contract resource rather than as an employee? I suspect the former, but the cases are somewhat different, and I thought it worth being sure.

@MadHatter: Well, my employment was in an Easter-EU country & I don't know the exact equivalences to English terminology. I was hired to work on a project for certain number of hours, didn't have fixed working hours, as long as the job was done or a fair attempt was made it was good on their part.

Supposing your condition is included in the contract, what are you going to do if the company (despite a very clear and unambiguous clause!) still asks you to use that technology? Can you do the same without that clause?

@IgorG, my idea was that if it is in the contract, I can politely refuse the task I am given with the specific technology. If it is not there, I feel that I can reasonably be blamed for not using a softwere which is so widely used.

@zabop I am ok with SQL or similar. - SQL is a language for interacting with relational databases, Excel is a spreadsheet tool. They are completely different tools for different problems. What do you plan to do if the problem you need to solve calls for a spreadsheet tool?

@SethR, I have not encountered such a problem which would better be solved by a spreadsheet tool, rather than with Pandas, letssay (that does not count as spreadsheet tool, right?). I do not have many years of experience, so this might change.

@zabop I do not have many years of experience, so this might change. I do have many years of experience and can guarantee it will. Your users are using Excel, so it is very likely someday you will be asked to deliver a solution that uses it in some way. Giving them a Python script using Pandas isn't going to cut it.

@SethR, alright, thanks :) Hopefully I'll leave my dread towards Excel behind at some point, then.

@virolino the real question might be "how to avoid people using the tool for the wrong applications" but that's for OP to clarify (and perhaps learn themselves to distinguish^^)

@FrankHopkins, yes, that probably would have been a better question, didn't think about it that way. Thanks!

As long as both sides agree and as long as it's legal, you can write anything into a contract. [Worker] will not be required to work when the outside temperature is below 30 degrees Fahrenheit. Of course that will limit the companies willing to sign such a contract. The whole thing seems rather "prima donna" to me, but you might succeed.

@sf02: yes, I was paid. I have dual expectations from a job: I want to be paid the amount agreed & I want to do useful things or things I learn from.The waste refered to the second part.

Maybe the fact that the company I worked for really didn't have enough people & wanted me to work for them quite a lot, put me to an unreasonably high horse, I might need to lower my expectations.

The underlying question about the actual problem you're facing seems to be: How do I make clear / ensure that I won't work with certain technologies in a future job? Related: What is the XY problem?

"Now I read that some other people are also not able to use that product well" - I would heavily question your assumption that those people would've done better with a technology that requires much more technical knowledge. You might not have made the same mistakes using Python, but I'm sure you'd have been able to avoid those mistakes, and other mistakes, just as easily using Excel.

@BernhardBarker While OP's idea is mostly absurd, Excel (at least old xls format) can work very badly with data. For example, just a week ago, a cell that was entered as,and showed clear int 132 in newest Excel app, showed 131.99994 when trying to parse the file in Python (with several libraries). Suffice to say that int(131.99994) <> 132. Not to speak of other well publicised, but hard to catch/predict rounding and date/ time bugs.

"I have dual expectations from a job: I want to be paid the amount agreed & I want to do useful things or things I learn from" - The first expectation is entirely reasonable. The second is entirely fanciful, IMO. A workplace is not an adventure playground built for the benefit of the employees.

@alephzero, yes, it is generally not, but why shouldn't I try to make it so? I am ok with working for companies which pay me less than industry average, for example, so if maximizing my salary is not a constraint, I have a way bigger variety of companies to choose from, among them I'll be more likely to find one which the second one is true. If I really go hard on this, I could always remain a research student or something like that, it lets me do (basically) what I want & gives me salary to live by (I don't want to do this, just included as an example way of reaching both goals).

@virolino it's OK for the company to use Excel, it's just that OP doesn't want to work with it.

I th8ink you're grossly under estimating how powerful excel is.

@dwjohnston It's used by the Wall St Journal to handle all the financial statistics.

@dwjohnston Just because it's powerful does not mean it's the correct tool in a number of cases. For example, I can't count the number of people I've found using Excel as a database when they legitimately needed proper ACID semantics. Excel quite often ends up being a case of the classic 'if all you have is a hammer' saying, people learn it and then try to use it for everything without thinking about whether it makes sense or not.

@AustinHemmelgarn No, what usually happens is that a super-user makes an excel based tool for himself, and then others start using it, and it grows out of control. Then, a clever developer converts them into applications