Python · Theory

for Loop in Python

Theory

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for Loop in Python

for walks each item in an iterable, one by one. Shape: for name in names: print(name). You can loop a list, a string, a tuple, dict keys, or range. range(5) is 0..4. range(1, 6) is 1..5. The stop is exclusive — that off-by-one mistake prints 1..6 when you wanted 1..5.

enumerate(names) gives index and value together: for i, n in enumerate(names):. Dry-run: for i in range(1, 4): print(i) → 1 then 2 then 3. Say the stop is exclusive before you write the code.

for Loop in Python — output — 1 2 3 4 5 each on a new line. range(1, 6) stops before 6.

Diagram

names = [Asha, Ravi, Neha]
         │
         ▼
   for x in names:
       Asha → Ravi → Neha

Exam tip

range stop is exclusive — say it clearly.

Example

# for loop
for i in range(1, 6):
    print(i)

for Loop in Python — output: 1 2 3 4 5 each on a new line. range(1, 6) stops before 6.

Short notes

Deffor x in iterable.
Rulerange stop is exclusive.
Rememberenumerate for index.

Python · Theory

for Loop in Python

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Theory

22/268

for Loop in Python

enumerate(names) gives index and value together: for i, n in enumerate(names):. Dry-run: for i in range(1, 4): print(i) → 1 then 2 then 3. Say the stop is exclusive before you write the code.

for Loop in Python — output — 1 2 3 4 5 each on a new line. range(1, 6) stops before 6.

Diagram

names = [Asha, Ravi, Neha]
         │
         ▼
   for x in names:
       Asha → Ravi → Neha

Exam tip

range stop is exclusive — say it clearly.

Example

# for loop
for i in range(1, 6):
    print(i)

for Loop in Python — output: 1 2 3 4 5 each on a new line. range(1, 6) stops before 6.

Short notes

Deffor x in iterable.
Rulerange stop is exclusive.
Rememberenumerate for index.

for Loop in Python

Example

Short notes

Questions

for Loop in Python

Example

Short notes

Questions