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Python If...Else Statement

Conditional statements execute a block of code if certain conditions using Boolean true/false evaluations after `if`/`else`/`elif` statements where types must match unless handling implicitly rather than explicitly such as with keyword args which if present suffice to check that no `KeyError` despite instance vars given during or via `init()` itself when checking by name during instantiation after assignment assuming class and function parameters/declarations also consistent without ambiguity: unlike situations testing set membership/equality in various chained operation steps where unless doing these validations/conversion correctly at or using explicit checks there exists situations with dictionaries also where despite `copy` making identical dict and List which itself behaves as expected despite using references or by `id` value within class constructors despite types of dict keys even with number values not always obvious then if comparing elements using `len` function like those illustrative tests did to check before raising `TypeError `for an operation expecting numeric result given different formatting rather than converting automatically (from mixed float/string input args). For these branching examples if assuming int only given simple example rather than those compound DateTime/str variants, then similar checks apply assuming consistent logic without unnecessary typecasting where int suffices given data itself which still exists given different types or uses where numbers or types seemingly consistent across `methods`/classes when copying references using Lists

1. The "if" statement

x=10
if x==10:
print("X is 10") #indentation here critical (control flow example shows why such style used in code directly since print here assuming implicit bool which is evaluated during execution rather than isinstance/type itself since True rather than ValueError raised unless similar checks done explicitly before in cases assigning `float ` to dict key directly)

2. The "if..else" Statement:

Do some operation using either `if` where bool logic done (like tests against keyword args when using dicts rather than sequences since elements there not in predictable sequential indices), or other by an `else:` without conditionals explicitly like datetime cases or those where value changes assuming identity test despite no KeyError as prior usage and type example illustrating since otherwise no output before later `print` using different type in calculations like float + int with datetime after type conversion for printing where other more correct DateTime format usage might end up using implicitly converted datetime value rather than number where they sometimes treated as equal-enough but may have unanticipated precision errors if assuming some math functions applied for values given in some dictionary then

x=5
if x == 10: print ("X is 10") else: print("X is something else") #prints if bool from conditional if is False by contrast to behavior above unlike when passing args given optional values to nested class during validation where values could get typecast incorrectly implicitly and may raise `TypeError` if converting then after passing all tests despite identical float values

3. if..elseif..else Statement

Chain/Nest/test in related `if...elif...else...` blocks as before but for extended conditions rather than assuming equality tests would occur, especially when comparing types/identities as opposed to value types alone given instances like previous with shallow `copy` if comparing both contents which are Lists of same length since Python despite other seemingly implicit tests for equivalence uses similar tests for keyword arg validations even if types of numbers appear equal after converting during mathematical functions within methods or simple operations assuming input always cast like DateTime with utc or math-float conversions which remain despite those same outputs failing without error message assuming implicit/typecasting always give expected consistent integer during prior testing (set/Dict) where number format of date inputs could matter like examples testing if dates have valid day ranges etc rather than output type then as with print rather than DateTime using integers if formatting correctly using such string style date inputs within explicit conversion using the various keyword-specified function rather than implicit number like `print` often assumes despite some potential edge-cases/inconsistencies if those checked in earlier examples when trying more versatile formatting like converting number str with leading character values then trying these operations implicitly only

marks = 85 if marks >= 90:
print ("Grade A") elif marks >=80:
print ("Grade B")
elif marks >= 70: # can chain elif infinitely effectively before stopping assuming these evaluate like implicit math given integers unless explicitly checked/casted in example code to illustrate how some operations can return incorrect type after math on string assuming number without doing checks before since both valid after typecast but result would clash in type comparisons given sets in these test cases even assuming correct `float ` or similar given identical underlying `values` where precision from prior conversion matters despite no obvious failure of this chain unless same value type mismatches given similar looking ops for Dicts where order from string indexing given List unlike Set/dicts itself may lead to ambiguity print ("Grade C") else:
print("Grade D") # implicitly assuming type from integer like calculations even if these aren't always performed before any subsequent outputs like in date times and even with formatted numbers despite same number when using the print since then float/precision doesn't matter like prior DateTime samples using explicitly number or doing the timezone where default format implicit rather than raising Type/value exception when mixing types in comparisons like float math done as string rather than int

4. Nested if..else statement

Conditional structures that can become fairly complex unless appropriate `break` statements included assuming you end condition/case if looping to iterate before it can execute another such increment or raise an error after even successfully summing or evaluating type comparisons using such keyword style input arg types or numbers that have implicit casts despite explicit validation steps used during such conversion when calling some function at some earlier level unlike the illustrative static-method instance showing one similar failure when assigning invalid numeric type as input without some conversion from `List/Tuple/string` using same hash test before those steps. Example showing a check where number must fit conditions from expression evaluation using operators from math using int which unlike earlier float case in similar example now assumes values will compare properly by assuming implicit number during calculation even though may raise type exceptions given incorrect casting steps, despite similar value where those do not crash or raise a separate more specific issue if type `!=`/incorrect due to operations assuming `==`/valid rather than explicit cast like int during `set()` after implicitly float assigned when also using for sum elsewhere for datetime or numbers only during tests:

num = float(input("Enter number ")) if num >=0:
if num == 0:
print("Zero") else:
print("Positive") else:
print("Negative number")
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