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README.md
vendored
14
README.md
vendored
@ -383,7 +383,7 @@ False
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#### 💡 Explanation:
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As per https://docs.python.org/2/reference/expressions.html#not-in
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As per https://docs.python.org/3/reference/expressions.html#membership-test-operations
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> Formally, if a, b, c, ..., y, z are expressions and op1, op2, ..., opN are comparison operators, then a op1 b op2 c ... y opN z is equivalent to a op1 b and b op2 c and ... y opN z, except that each expression is evaluated at most once.
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@ -1280,7 +1280,7 @@ SyntaxError: EOF while scanning triple-quoted string literal
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```
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#### 💡 Explanation:
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+ Python supports implicit [string literal concatenation](https://docs.python.org/2/reference/lexical_analysis.html#string-literal-concatenation), Example,
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+ Python supports implicit [string literal concatenation](https://docs.python.org/3/reference/lexical_analysis.html#string-literal-concatenation), Example,
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```
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>>> print("wtf" "python")
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wtfpython
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@ -1696,7 +1696,7 @@ But I thought tuples were immutable...
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#### 💡 Explanation:
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* Quoting from https://docs.python.org/2/reference/datamodel.html
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* Quoting from https://docs.python.org/3/reference/datamodel.html
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> Immutable sequences
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An object of an immutable sequence type cannot change once it is created. (If the object contains references to other objects, these other objects may be mutable and may be modified; however, the collection of objects directly referenced by an immutable object cannot change.)
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@ -1858,7 +1858,7 @@ a, b = a[b] = {}, 5
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#### 💡 Explanation:
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* According to [Python language reference](https://docs.python.org/2/reference/simple_stmts.html#assignment-statements), assignment statements have the form
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* According to [Python language reference](https://docs.python.org/3/reference/simple_stmts.html#assignment-statements), assignment statements have the form
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```
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(target_list "=")+ (expression_list | yield_expression)
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```
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@ -2625,7 +2625,7 @@ def similar_recursive_func(a):
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AssertionError: Values are not equal
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```
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* As for the fifth snippet, most methods that modify the items of sequence/mapping objects like `list.append`, `dict.update`, `list.sort`, etc. modify the objects in-place and return `None`. The rationale behind this is to improve performance by avoiding making a copy of the object if the operation can be done in-place (Referred from [here](http://docs.python.org/2/faq/design.html#why-doesn-t-list-sort-return-the-sorted-list)).
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* As for the fifth snippet, most methods that modify the items of sequence/mapping objects like `list.append`, `dict.update`, `list.sort`, etc. modify the objects in-place and return `None`. The rationale behind this is to improve performance by avoiding making a copy of the object if the operation can be done in-place (Referred from [here](https://docs.python.org/3/faq/design.html#why-doesn-t-list-sort-return-the-sorted-list)).
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* Last one should be fairly obvious, mutable object (like `list`) can be altered in the function, and the reassignation of an immutable (`a -= 1`) is not an alteration of the value.
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@ -2655,7 +2655,7 @@ def similar_recursive_func(a):
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#### 💡 Explanation:
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- It might appear at first that the default separator for split is a single space `' '`, but as per the [docs](https://docs.python.org/2.7/library/stdtypes.html#str.split)
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- It might appear at first that the default separator for split is a single space `' '`, but as per the [docs](https://docs.python.org/3/library/stdtypes.html#str.split)
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> If sep is not specified or is `None`, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace. Consequently, splitting an empty string or a string consisting of just whitespace with a None separator returns `[]`.
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> If sep is given, consecutive delimiters are not grouped together and are deemed to delimit empty strings (for example, `'1,,2'.split(',')` returns `['1', '', '2']`). Splitting an empty string with a specified separator returns `['']`.
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- Noticing how the leading and trailing whitespaces are handled in the following snippet will make things clear,
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@ -3576,7 +3576,7 @@ What makes those dictionaries become bloated? And why are newly created objects
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print(dis.dis(f))
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```
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* Multiple Python threads won't run your *Python code* concurrently (yes, you heard it right!). It may seem intuitive to spawn several threads and let them execute your Python code concurrently, but, because of the [Global Interpreter Lock](https://wiki.python.org/moin/GlobalInterpreterLock) in Python, all you're doing is making your threads execute on the same core turn by turn. Python threads are good for IO-bound tasks, but to achieve actual parallelization in Python for CPU-bound tasks, you might want to use the Python [multiprocessing](https://docs.python.org/2/library/multiprocessing.html) module.
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* Multiple Python threads won't run your *Python code* concurrently (yes, you heard it right!). It may seem intuitive to spawn several threads and let them execute your Python code concurrently, but, because of the [Global Interpreter Lock](https://wiki.python.org/moin/GlobalInterpreterLock) in Python, all you're doing is making your threads execute on the same core turn by turn. Python threads are good for IO-bound tasks, but to achieve actual parallelization in Python for CPU-bound tasks, you might want to use the Python [multiprocessing](https://docs.python.org/3/library/multiprocessing.html) module.
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* Sometimes, the `print` method might not print values immediately. For example,
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