python: improve notes on loops
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1 changed files with 28 additions and 78 deletions
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@ -6,28 +6,6 @@ tags: [python]
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# Loops in Python
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# Loops in Python
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## While
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```python
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count = 0
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print('Starting')
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while count < 10:
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print(count, '', end='')
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count += 1
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print() # not part of the while loop
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print('Done')
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"""
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Starting
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0 1 2 3 4 5 6 7 8 9
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Done
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"""
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```
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> There are no `do while` loops in Python
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## For
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## For
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There are three main types of `for` loop in Python and they all use the `for...in` clause:
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There are three main types of `for` loop in Python and they all use the `for...in` clause:
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@ -62,60 +40,33 @@ There are three main types of `for` loop in Python and they all use the `for...i
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print(f"Index {index}: {fruit}")
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print(f"Index {index}: {fruit}")
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```
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```
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### Further examples of `for in range()` loops
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### Loop in increments greater than 1
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// TODO: segment the examples into dedicated sections
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The following loop increments by 2 on each iteration
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```python
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```py
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# Loop over a set of values in a range
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print('Print out values in a range')
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for i in range(0, 10):
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print(i, ' ', end='')
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print()
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print('Done')
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"""
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Print out values in a range
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0 1 2 3 4 5 6 7 8 9
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Done
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"""
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# Now use values in a range but increment by 2
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print('Print out values in a range with an increment of 2')
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for i in range(0, 10, 2):
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for i in range(0, 10, 2):
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print(i, ' ', end='')
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print(i, ' ', end='')
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print()
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print()
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print('Done')
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"""
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# 0 2 4 6 8
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Print out values in a range with an increment of 2
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```
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0 2 4 6 8
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Done
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"""
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# Now use an 'anonymous' loop variable
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### Break and continue
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for _ in range(0, 10):
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print('.', end='')
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print()
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print('-' * 25)
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#### Break
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# Illustrates use of break statement
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```py
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print('Only print code if all iterations completed')
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num = int(input('Enter a number from 1-6 to check for: '))
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num = int(input('Enter a number to check for: '))
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for i in range(0, 6):
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for i in range(0, 6):
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if i == num:
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if i == num:
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break
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break
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print(i, ' ', end='')
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print(i, ' ')
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print('Done')
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```
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"""
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#### Continue
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Only print code if all iterations completed
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Enter a number to check for: 7
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0 1 2 3 4 5 Done
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"""
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# Illustrates use of continue statement
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```py
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for i in range(0, 10):
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for i in range(0, 10):
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print(i, ' ', end='')
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print(i, ' ', end='')
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if i % 2 == 1:
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if i % 2 == 1:
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@ -137,26 +88,25 @@ we love even numbers
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we love even numbers
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we love even numbers
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9 Done
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9 Done
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"""
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"""
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```
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# Illustrates use of else statement with a for loop
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## While
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print('Only print code if all iterations completed')
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num = int(input('Enter a number to check for: '))
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```python
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for i in range(0, 6):
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count = 0
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if i == num:
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print('Starting')
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break
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while count < 10:
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print(i, ' ', end='')
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print(count, '', end='')
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else:
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count += 1
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print()
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print('All iterations successful')
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print() # not part of the while loop
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print('Done')
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print('Done')
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"""
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"""
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Only print code if all iterations completed
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Starting
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Enter a number to check for: 6
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0 1 2 3 4 5 6 7 8 9
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0 1 2 3 4 5
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All iterations successful
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Done
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Done
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"""
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"""
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```
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```
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> There are no `do while` loops in Python
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