String Operations
The Python slice syntax is very powerful. Not only does it allow for extraction of portions of a string, but it also allows for much more complex types of extractions. The textbook does not demonstrate some of the more powerful portions of the slicing syntax; It allows negative arguments, has a third optional argument, and even handles the omission of arguments. In this activity you will explore some of these other uses of string slices.
Write how Python would evaluate each of the following expressions.
| Expression | Output |
|---|---|
'Hello, World!'[6:11]
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'Hello, World!'[6:-1]
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'Hello, World!'[-6:-1]
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'Hello, World!'[6:]
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'Hello, World!'[:5]
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'Hello, World!'[0:-1:2]
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'Hello, World!'[4::-1]
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Rewrite each of the functions below to use the for character in
string style of loop.
| Original Program | Altered Program |
|---|---|
def a_func(my_str):
acc = ''
for i in range(len(my_str)):
char = my_str[i]
if char != ' ':
acc += char
return acc
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def a_func(my_str):
vowels = 'aeiou'
acc = ''
for i in range(len(my_str)):
char = my_str[i]
if char in vowels:
acc += '*'
else:
acc += char
return acc
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def a_func(my_str, your_str):
acc = ''
for i in range(len(my_str)):
if my_str[i] != '*':
acc += my_str[i]
else:
acc += your_str[i]
return acc
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