Does Python limit the number of items that can be stored in a dictionary?
NO, there is no fixed size limit imposed by Python on a dictionary. A dictionary can grow to whatever size is allowed by the computer running the program based on its operating system and memory.
So there’s actually a difference on Windows, macOS, Linux etc. about how many key-value pairs can be stored inside a dictionary?
There is no real limit given sufficient memory resources. However, performance will degrade significantly as the number of entries increases to 10’s of millions. Generally speaking, we needn’t be too concerned if the number of entries is only a few thousand.
More specifically the address size of the OS. A 64 bit OS can address 16 Exabytes compared to a 32 bit OS which can address only 4 Gigabytes. More memory storage means larger dictionaries. This also equates to larger chunks of data throughput with the CPU making a 64 bit OS faster and more efficient in processing those large dictionaries.