Hướng dẫn python -m flag example

Although this is already answered, however, the fastest way to compute such result is usually using np.where as follows:

Nội dung chính

• Turtle graphics
• How do you implement a flag in Python?
• Can we use flag in Python?
• What is flag in Python programming?
• How do you make a turtle flag in Python?

Nội dung chính

• Turtle graphics
• How do you implement a flag in Python?
• Can we use flag in Python?
• What is flag in Python programming?
• How do you make a turtle flag in Python?

import pandas as pd
import pandas_datareader as dr
import numpy as np
from datetime import date

df = dr.data.get_data_yahoo('SPY',start='01-01-2019',end=date.today())

df['HC'] = df['Close'].rolling(20).max() 
df['LC'] = df['Close'].rolling(20).min() 

There is a nested logic in the following:

1. Create an empty array
2. Replace Values with -1 under condition
3. Replace Values with 1 under condition

df['Flag'] = np.where((df.Close == df.HC), 1, 
         np.where(df.Close == df.LC, -1, np.full(df.Close.count(), np.nan)))
df.Flag.fillna(method='ffill', inplace=True)

In terms of performance:

%%timeit
df['Flag'] = np.where((df.Close == df.HC), 1, 
         np.where(df.Close == df.LC, -1, np.full(df.Close.count(), np.nan)))
df.Flag.fillna(method='ffill', inplace=True)

912 µs ± 49.2 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)

This is definitely better that loops or nested if conditions.

For example @Tim Mironov answer:

%%timeit
pos_indexes = (df.Close == df.HC)
neg_indexes = (df.Close == df.LC)

df.loc[pos_indexes, 'Good_Flag'] = 1
df.loc[neg_indexes, 'Good_Flag'] = -1

df.fillna(method='ffill', inplace=True)

4.43 ms ± 92 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

Here, we will be making “The Great Indian Flag” using Python Turtle Graphics. Here, we will be using many turtle functions like begin_fill(), end_fill() to fill color inside the Flag, penup(), pendown(), goto() etc to reaching the target.

Turtle graphics

In computer graphics, turtle graphics are vector graphics using a relative cursor upon a Cartesian plane. Turtle is a drawing board-like feature thatlets us command the turtle and draw using it.

Features of turtle graphics:

• forward(x): moves the pen in forward direction by x units.
• backward(x): moves the pen in the backward direction by x units.
• right(x): rotate the pen in the clockwise direction by an angle x.
• left(x): rotate the pen in the anticlockwise direction by an angle x.
• penup(): stop drawing of the turtle pen.
• pendown(): start drawing of the turtle pen.
• begin_fill(): starts filling the color inside the shape.
• fillcolor(“color_name”): sets the color to be filled.
• end_fill(): stops filling the color.

Approach

1. import the turtle modules.

import turtle

2. Get a screen to draw on.

screen = turtle.Screen()

3. Define an instance for turtle(here “t”).

4.For making an Indian Flag let’s divide the process into 4 steps:

• The rectangle with orange color.
• Then the middle rectangle.
• Then the last Green Rectangle.
• Then Ashoka Chakra inside the middle rectangle.

5. Here dimensions of all three Rectangles are (800 units x 167 units), which makes up dimensions of the flag as (800 units x 501 units).

6. The turtle starts from coordinates (-400, 250).

7. Then from that position it makes the First rectangle of orange color.

8. Then from the ending point of the first rectangle, Turtle makes the Second rectangle of no color.

9. Then the Third green color rectangle is made. Now for Ashoka Chakra, we need to perform a set of operations

• A Big Blue circle and a white circle just smaller than blue.
• Set of small blue circles on the inner lining of a blue and white circle.
• And finally spokes inside the two blue and white circles starting from the Centre towards the outer direction.

10. Finally, The pride of one’s Nation is ready. 

Below is the implementation of the above approach:

Python

import turtle

from turtle import*

screen = turtle.Screen()

t = turtle.Turtle()

speed(0)

t.penup()

t.goto(-400, 250)

t.pendown()

t.color("orange")

t.begin_fill()

t.forward(800)

t.right(90)

t.forward(167)

t.right(90)

t.forward(800)

t.end_fill()

t.left(90)

t.forward(167)

t.color("green")

t.begin_fill()

t.forward(167)

t.left(90)

t.forward(800)

t.left(90)

t.forward(167)

t.end_fill()

t.penup()

t.goto(70, 0)

t.pendown()

t.color("navy")

t.begin_fill()

t.circle(70)

t.end_fill()

t.penup()

t.goto(60, 0)

t.pendown()

t.color("white")

t.begin_fill()

t.circle(60)

t.end_fill()

t.penup()

t.goto(-57, -8)

t.pendown()

t.color("navy")

for i in range(24):

    t.begin_fill()

    t.circle(3)

    t.end_fill()

    t.penup()

    t.forward(15)

    t.right(15)

    t.pendown()

t.penup()

t.goto(20, 0)

t.pendown()

t.begin_fill()

t.circle(20)

t.end_fill()

t.penup()

t.goto(0, 0)

t.pendown()

t.pensize(2)

for i in range(24):

    t.forward(60)

    t.backward(60)

    t.left(15)

turtle.done()

 
 Output:

https://media.geeksforgeeks.org/wp-content/uploads/20200925192638/Indian-Flag.mp4

How do you implement a flag in Python?

Python Language Regular Expressions (Regex) Flags For some special cases we need to change the behavior of the Regular Expression, this is done using flags. Flags can be set in two ways, through the flags keyword or directly in the expression.

Can we use flag in Python?

A flag in Python acts as a signal to the program to determine whether or not the program as a whole or a specific section of the program should run. In other words, you can set the flag to True and the program will run continuously until any type of event makes it False.

What is flag in Python programming?

(Those are the constants that Python uses.) Any data type can be used as a flag. An integer could have the value 1 if something happened and 0 if it did not. BUT because it is an integer, and the language will allow it to have any integer value, the flag could accidently be set to an inconsistent value, like 23.

How do you make a turtle flag in Python?

1. import the turtle modules. 2. Get a screen to draw on..

The rectangle with orange color..

Then the middle rectangle..

Then the last Green Rectangle..

Then Ashoka Chakra inside the middle rectangle..