Python · Theory

itertools

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itertools

itertools is about functions that take/return functions, or itertools helpers (chain, cycle, combinations). map/filter/lambda are the fresher versions.

Keep it concrete — map(str.upper, ["a","b"]) → A B. itertools.chain([1],[2,3]) → 1 2 3.

itertools — output — [1, 2, 3] then [('A','B'), ('A','C'), ('B','C')].

Exam tip

One tiny map/filter or itertools line + output.

Example

# itertools
import itertools
print(list(itertools.chain([1], [2, 3])))
print(list(itertools.combinations("ABC", 2)))

itertools — output: [1, 2, 3] then [('A','B'), ('A','C'), ('B','C')].

Short notes

Defitertools works with functions or iterators.
Usemap/filter or itertools.
TrapOverusing lambda when def is clearer.

Python · Theory

itertools

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Theory

99/268

itertools

itertools is about functions that take/return functions, or itertools helpers (chain, cycle, combinations). map/filter/lambda are the fresher versions.

Keep it concrete — map(str.upper, ["a","b"]) → A B. itertools.chain([1],[2,3]) → 1 2 3.

itertools — output — [1, 2, 3] then [('A','B'), ('A','C'), ('B','C')].

Exam tip

One tiny map/filter or itertools line + output.

Example

# itertools
import itertools
print(list(itertools.chain([1], [2, 3])))
print(list(itertools.combinations("ABC", 2)))

itertools — output: [1, 2, 3] then [('A','B'), ('A','C'), ('B','C')].

Short notes

Defitertools works with functions or iterators.
Usemap/filter or itertools.
TrapOverusing lambda when def is clearer.

itertools

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itertools

Example

Short notes

Questions