Word: The meaning of "by"

[Anna.ha]

Could anyone show/correct me the meaning of "by" in the following contexts?

1- By the time I came to the party, she had left. Does "by" mean "during" in this sentence?

2- I'll show you some ideas by pictures. Does "by" mean "by showing you", "by giving you" or what"? Can "by" be replaced by "with" or "in" or other prepositions in this context?

3- By regulations, your lessons start at 9h in the morning. Does "by" here mean "according to". I suppose so but am not certain since I think "according to" refers to something defined before or something that's already existed.

4- In muslim countries, alcoholic drinks are not allowed by law.

Thanks

[Alan]

Hi Anna,

(1) Here we have the suggestion 'when the time of my arrival took place.'
(2) I would suggest 'in'.
(3) Here I would use: 'According to the regulations'.
(4) 'By law' is acceptable.

Alan
_________________
English as a Second Language
You can read my ESL story Present Simple

[Anna.ha]

1- I got it.
2- You meant the sentence has the same meaning after "by" is replaced by "in", Alan?
3- OK, "according to..." yields much more hits than "by regulations". Does "by regulations" sound natural and have the same meaning with "according to...", Alan?
4- I supposed "by law" is a fixed expression and no way other than learn it by heart. - correct ?

I am trying to compare to see if the followings have the same meaning?

(1) According to the regulations..., someone have to do something.
(2) In principle, someone have to do something.

Please continue helping me.

Thanks