def dictionary_data():
sys_logging.info(f'------dictionary data-------')
create_dictionary()
access_dictionary()
reassign_dictionary()
delete_dictionary()
dict_built_in_method()
def array_from_numerical_ranges():
# np.arange(start, stop, step, dtype)
# start: the start of an interval. If omitted, defaults to 0
# stop: the end of an interval. (not including this number)
# step: Spacing between values, default is 1
# dtype: data type of resulting ndarray. If not given, data type of input is used.
x = np.arange(5)
sys_logging.info(x)
y = np.arange(10, 20, 2)
sys_logging.info(y)
# np.linspace(start, stop, num, endpoint, retstep, dtype)
# start: the starting value of the sequence
# stop: the end value of the sequence, included in the sequence if endpoint set to true
# num: the number of evenly spaced samples to be generated. Default is 50
# endpoint: True by default, hence the stop value is included in the sequence. If false, it is not include
# retstep: If true, returns samples and step between the consecutive numbers
# dtype: Data type of output ndarray
z = np.linspace(10, 20, 5)
sys_logging.info(z)
a = np.linspace(10, 20, 5, endpoint=False)
sys_logging.info(a)
# np.logspace(start, stop, num, endpoint, base, dtype)
# start: the starting point of the sequence is start's start
# base: base of log space, default is 10
b = np.logspace(1, 2, num=10)
sys_logging.info(b)
def broadcast():
x = np.array([[1], [2], [3]])
y = np.array([4, 5, 6])
b = np.broadcast(x, y)
for i in b:
sys_logging.info(i)
sys_logging.info(x + y)
def thread_method():
thread_one = Thread(target=function_one, args=(10, 'ThreadOne'))
thread_one.start()
thread_two = Thread(target=function_two, args=(5, 'thread two'))
thread_two.start()
thread_two.join()
sys_logging.info('print after child threads')
def delete():
sys_logging.info('np.delete')
d = np.arange(12).reshape((3, 4))
sys_logging.info(d)
sys_logging.info(np.delete(d, 5))
sys_logging.info(np.delete(d, 1, axis=0))
e = np.arange(10)
sys_logging.info(np.delete(e, np.s_[::2]))
def lock_method():
s_counter = SharedCounter()
t1 = threading.Thread(target=task, args=(s_counter, 't1',))
t1.start()
t2 = threading.Thread(target=task, args=(s_counter, 't2',))
t2.start()
t1.join()
t2.join()
sys_logging.info(f'Counter: {s_counter.counter}')
def delete_set():
sys_logging.info(f'------delete set-------')
numbers = {3, 2, 1, 4, 5, 6, 7}
sys_logging.info(f'numbers set {numbers}')
numbers.discard(3) # would not raise a KeyError if the value doesn't exist
sys_logging.info(f'numbers.discard(3) {numbers}')
numbers.remove(2) # would raise a KeyError if the value exist
sys_logging.info(f'numbers.remove(3) {numbers}')
a = numbers.pop()
sys_logging.info(f'numbers.pop() a = {a}, numbers = {numbers}')
def transpose_operation():
# transpose operation
# transpose(): np.transpose(ndarray), permutes the dimensions of an array
# ndarray.T: Same as self.transpose
# rollaxis: rolls the specified axis backwards
# swapaxis: Interchange the two axis of an array
sys_logging.info(f'Transpose operation')
a = np.arange(0, 60, 5)
a = a.reshape(3, 4)
sys_logging.info(a.T)
def change_dimensions():
# Changing dimensions
# broadcast: Produce an object that mimics broadcasting
# broadcast_to: Broadcast an array to a new shape
# expand_dims: Expands the shape of an array
# squeeze: Removes single-dimensional entries from the shape of array
sys_logging.info(f'Changing dimensions')
broadcast()
broadcast_to()
expand_dims()
squeeze()
def rename_columns():
header(
"10.1 df.rename(columns = {'avg_precipitation': 'avg_rain'}, inplace = True)"
)
df.rename(columns={'avg_precipitation': 'avg_rain'}, inplace=True)
sys_logging.info(df.head())
header(
"10.2 df.columns = ['month', 'av_hi', 'av_lo', 'rec_hi', 'rec_lo', 'av_rain']"
)
df.columns = ['month', 'av_hi', 'av_lo', 'rec_hi', 'rec_lo', 'av_rain']
sys_logging.info(df.head())
def thread_basic_print():
# This returns the number of alive(currently) Thread objects.
# This is equal to the length the of the list that enumerate() returns.
sys_logging.info(f'threading.active_count() = {threading.active_count()}')
sys_logging.info(f'current thread = {threading.current_thread()}')
sys_logging.info(f'current thread id = {threading.get_ident()}')
# This returns a list of all alive(currently) Thread objects.
# This includes the main thread, daemonic threads, and dummy thread objects created by current_thread().
# This obviously doesn’t include terminated threads as well as those that haven’t begun yet.
sys_logging.info(f'thread enumerate = {threading.enumerate()}')
sys_logging.info(f'main thread = {threading.main_thread()}')
def array_from_existing_data():
x = [(1, 2, 3), (2, 3, 4)]
a = np.asarray(x, dtype=float)
sys_logging.info(a)
# s = 'Hello World'
# b = np.frombuffer(s, dtype='S1')
# sys_logging.info(b)
list_a = range(5)
it = iter(list_a)
# use iterator to create ndarray
c = np.fromiter(it, dtype=float)
sys_logging.info(c)
def stack():
a = np.array([[1, 2], [3, 4]])
b = np.array([[5, 6], [7, 8]])
sys_logging.info(f'hstack \n {np.hstack((a, b))}')
sys_logging.info(f'vstack \n {np.vstack((a, b))}')
sys_logging.info(f'stack axis = 0 \n {np.stack((a, b))}')
sys_logging.info(f'stack axis = 1 \n {np.stack((a, b), axis=1)}')
def reassign_dictionary():
sys_logging.info(f'------reassign dictionary------')
numbers = {1: 1, 2: 2, 3: 3}
sys_logging.info(f'thr original numbers = {numbers}')
numbers[2] = 4
sys_logging.info(f'update numbers[2] = 4, numbers = {numbers}')
numbers[4] = 4
sys_logging.info(f'add a new element numbers[4] = 4, numbers = {numbers}')
def nd_array_object():
a = np.array([1, 2, 3])
sys_logging.info(a)
b = np.array([[1, 2], [3, 4]])
sys_logging.info(b)
c = np.array([1, 2, 3, 4, 5], ndmin=2)
sys_logging.info(c)
d = np.array([1, 2, 3, 4], dtype=complex)
sys_logging.info(d)
def deep_copy():
sys_logging.info(f'------ deep copy ------')
a = [1, 23, [4, 5], 'Stephen']
sys_logging.info(f'a = {a}, id(a) = {id(a)}')
b = copy.deepcopy(a)
sys_logging.info(f'b = {b}, id(b) = {id(b)}')
b[2][0] = 23
b[3] = 'Young'
sys_logging.info(f'a = {a}, b = {b}, id(a) = {id(a)}, id(b) = {id(b)}')
def shallow_copy():
sys_logging.info(f'------- shallow copy ------')
a = [1, 23, [4, 5], 'Stephen']
sys_logging.info(f'a = {a}, id(a) = {id(a)}')
b = copy.copy(a)
sys_logging.info(f'b = {b}, id(b) = {id(b)}')
b[2][0] = 45
b[3] = 'Young'
sys_logging.info(f'a = {a}, b = {b}, id(a) = {id(a)}, id(b) = {id(b)}')
def condition_task():
main_cond = threading.Condition()
main_si = SomeItem()
c_thread = Thread(name='Consumer-Thread',
target=consumer,
args=(main_si, main_cond))
c_thread.start()
p_thread = Thread(name='Producer-Thread',
target=producer,
args=(
main_si,
main_cond,
))
p_thread.start()
c_thread.join()
p_thread.join()
sys_logging.info(f'Main Done')
def load_hard_coded_data():
# 1. load hard-coded data into a dataframe
header(f'1. Load hard-coded data into df')
global df
df = pd.DataFrame(
[['Jan', 58, 42, 74, 22, 2.95], ['Feb', 61, 45, 78, 26, 3.02],
['Mar', 65, 48, 84, 25, 2.34], ['Apr', 67, 50, 92, 28, 1.02],
['May', 71, 53, 98, 35, 0.48], ['Jun', 75, 56, 107, 41, 0.11],
['Jul', 77, 58, 105, 44, 0], ['Aug', 77, 59, 102, 43, 0.03],
['Sep', 77, 57, 103, 40, 0.17], ['Oct', 73, 54, 96, 34, 0.81],
['Nov', 64, 48, 84, 30, 1.7], ['Dec', 58, 42, 73, 21, 2.56]],
index=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11],
columns=[
'month', 'avg_high', 'avg_low', 'record_high', 'record_low',
'avg_precipitation'
])
sys_logging.info(df)
def array_creation_routines():
x = np.empty([3, 2], dtype=int)
sys_logging.info(x)
y = np.zeros(5)
sys_logging.info(y)
z = np.zeros([
5,
], dtype=int)
sys_logging.info(z)
a = np.zeros([2, 2], dtype=[('x', 'i4'), ('y', 'i4')])
sys_logging.info(a)
def iterating_over_array():
a = np.arange(0, 60, 5)
a = a.reshape(3, 4)
sys_logging.info(a)
for x in np.nditer(a, flags=['c_index']):
sys_logging.info(x)
# broadcasting iterating
sys_logging.info(f'start broadcasting iterating')
b = np.array([1, 2, 3, 4])
for x, y in np.nditer([a, b]):
sys_logging.info(f'{x}:{y}')
def data_assignment():
header(f"9.1 df.loc[9, ['avg_precipitation']] = 101.3")
df.loc[9, ['avg_precipitation']] = 101.3
sys_logging.info(df.iloc[9:11])
header(f"9.2 df.loc[9, ['avg_precipitation']] = np.nan")
df.loc[9, ['avg_precipitation']] = np.nan
sys_logging.info(df.iloc[9:11])
header(f"9.3 df.loc[:,['avg_low']] = np.array([5]*len(df))")
df.loc[:, 'avg_low'] = np.array([5] * len(df))
sys_logging.info(df.head())
header(f"9.4 df['avg_day'] = (df.avg_low + df.avg_high)/2")
df['avg_day'] = (df.avg_low + df.avg_high) / 2
sys_logging.info(df.head())
def event_task(event):
event_set = event.wait()
sys_logging.info(f'{threading.current_thread()}')
if event_set:
sys_logging.info(f'Event received, releasing thread...')
else:
sys_logging.info(f'Time out, moving ahead without event')
def increment(self, name):
sys_logging.info(f'Waiting for a lock at {name}')
self.lock.acquire()
sys_logging.info(f'{name} Acquired a lock, counter value = {self.counter}')
self.counter += 1
self.lock.release()
sys_logging.info(f'{name} Released a lock, counter value = {self.counter}')
def update_set():
sys_logging.info(f'------update set------')
numbers = {1, 3, 4, 5, 8}
numbers.add(3.5)
sys_logging.info(f'numbers.add(3.5). numbers = {numbers}')
numbers.update({1, 3, 4, 9}, {'a', 'b'})
sys_logging.info(f'numbers.update() method. numbers = {numbers}')
def barrier_thread(barrier, timeout):
thread_name = threading.current_thread().getName()
sys_logging.info(f'{thread_name} is start')
time.sleep(timeout)
if thread_name == 'Thread-Three':
barrier.abort()
return
sys_logging.info(f'{thread_name} is ready')
try:
barrier.wait()
except threading.BrokenBarrierError:
sys_logging.info(f'{thread_name} is excepted')
finally:
sys_logging.info(f'{thread_name} is finished')
def expand_dims():
d = np.array([[1, 2], [3, 4]])
e = np.expand_dims(d, axis=0)
f = np.expand_dims(d, axis=1)
g = np.expand_dims(d, axis=2)
sys_logging.info(f'shape = {e.shape} \n {e}')
sys_logging.info(f'shape = {f.shape} \n {f}')
sys_logging.info(f'shape = {g.shape} \n {g}')
def create_list():
# python list can hold different types of values
sys_logging.info(f'------start create list------')
colors = ['red', 'green', 'blue']
days = ['Monday', 'Tuesday', 'Wednesday', 4, 5, 6, 7]
sys_logging.info(colors)
sys_logging.info(f'create days {days} id = {id(days)}')
return days
def get_second_line():
sys_logging.info(f'start second line')
second_acquire = rlock.acquire()
sys_logging.info(f'second acquire = {second_acquire}')
try:
with open('write.txt', 'r') as write:
second_line = write.readlines()
sys_logging.info(f'second: {second_line}')
finally:
rlock.release()
def load_file_data():
header(f'2. load file data')
global df
df = pd.read_csv('colors.csv')
sys_logging.info(df)
header(f'3.1 df.head()')
sys_logging.info(df.head())
header(f'3.2 df.tail(3)')
sys_logging.info(df.tail(3))