跟着我们一起学 Python 30天课程-第5天-条件和循环I(Conditions & Loops I)

age = input('Please enter your age')
if(int(age) >= 18):
  print('You are allowed to enter the club')
else:
  print('Sorry! you are not allowed!')

exam_score = input('Enter your exam score')
if(int(exam_score) > 90):
  print('You have got grade A+')
elif(int(exam_score) > 80):
  print('You have got grade A')
else:
  print('You have got grade B')

is_adult = True
is_licensed = True

if(is_adult and is_licensed): ## In JavaScript && is used instead of 'and'
  print('You are allowed to drive')
else:
  print('You are not allowed to drive')

if(10 > 8):
  print('Such a silly logic. I will get printed')
else:
  print('I will never get printed')
  print('I am not get printed coz I am indented')

# Now without indentation
if(10 > 8):
  print('Such a silly logic. I will get printed')
else:
  print('I will never get printed')
print('I will be printed anyways coz I am not indented')
# The above line gets printed always as interpreter treats it as a new line

username = 'santa' # bool('santa') => True
password = 'superSecretPassword' # bool('superSecretPassword') => True
if username and password:
  print('Details found')
else:
  print('Not found')

is_single = True
message = 'You can date' if is_single else 'you cannot date'
# result = (value 1) if (condition is truthy) else (value 2)
print(message) # You can date

knows_javascript = True
knows_python = True

if(knows_javascript or knows_python): # doesn't depend on value of knows_python
  print('Javscript or python developer')
else:
  print('Some other developer')

knows_javascript = False
knows_python = True

if(knows_javascript and knows_python): # doesn't depend on value of knows_python
  print('Javscript or python developer')
else:
  print('Some other developer')

print(10 > 100) # False
print(10 < 100) # True
print(10 == 10) # True
print(10 != 50) # True
print(2 > 1 and 2 > 0) # True
print(not(True)) # False
print(not False) # True

print(True == True) #True
print('' == 1) # False
print([] == 1) # False
print(10 == 10.0) # True
print([] == []) # True

print(True is True) # True
print('' is 1) # False
print([] is 1) # False
print(10 is 10.0) # False
print([] is []) # False

for item in 'Python': # String is iterable
  print(item) # prints all characters of the string

for item in [1,2,3,4,5]: # List is iterable
    print(item) # prints all numbers one at a time

for item in {1,2,3,4,5}: # Set is iterable
    print(item)

for item in (1,2,3,4,5): # Tuple is iterable
    print(item)

player = {
  'firstname': 'Virat',
  'lastname': 'Kohli',
  'role': 'captain'
}

for item in player: # iterates over the keys of player
  print(item) # prints all keys

for item in player.keys(): 
  print(item) # prints all keys

for item in player.values():
  print(item) # prints all values

for item in player.items():
  print(item) # prints key and value as tuple

for key, value in player.items():
  print(key, value) # prints key and value using unpacking

for item in range(10):
  print('python') # prints python 10 times

for item in range(0,10,1):
    print('hello') # prints hello 10 times

for item in range(0, 10, 2):
    print('hii') # prints hii 5 times 

for item in range(10, 0, -1):
    print(item) # prints in reverse order

print(list(range(10))) # generates a list of 10 items

for key, value in enumerate(range(10)): # using unpacking techique 
  print(f'key is {key} and value is {value}') # prints key and value at the same time