📅  最后修改于: 2020-10-29 01:00:06             🧑  作者: Mango
在Python,for循环用于print各种模式。印刷各种图案是面试中最常见的编程问题。多个for循环用于print模式,其中第一个外部循环用于print行数,而内部循环用于print列数。大多数模式都使用以下概念。
在本教程中,我们将讨论一些常见的模式。
在本节中,我们将学习常见的金字塔模式。
范例-
# This is the example of print simple pyramid pattern
n = int(input("Enter the number of rows"))
# outer loop to handle number of rows
for i in range(0, n):
# inner loop to handle number of columns
# values is changing according to outer loop
for j in range(0, i + 1):
# printing stars
print("* ", end="")
# ending line after each row
print()
输出:
*
* *
* * *
* * * *
* * * * *
说明:
在上面的代码中,我们已初始化n变量以输入模式的行数。我们输入n = 5,外部for循环的范围将是0到4。
范例-
# This is the example of print simple reversed right angle pyramid pattern
rows = int(input("Enter the number of rows:"))
k = 2 * rows - 2 # It is used for number of spaces
for i in range(0, rows):
for j in range(0, k):
print(end=" ")
k = k - 2 # decrement k value after each iteration
for j in range(0, i + 1):
print("* ", end="") # printing star
print("")
输出:
*
* *
* * *
* * * *
* * * * *
代码-
rows = int(input("Enter the number of rows: "))
# the outer loop is executing in reversed order
for i in range(rows + 1, 0, -1):
for j in range(0, i - 1):
print("*", end=' ')
print(" ")
输出:
Enter the number of rows: 5
* * * * *
* * * *
* * *
* *
*
代码-
n = int(input("Enter the number of rows: "))
m = (2 * n) - 2
for i in range(0, n):
for j in range(0, m):
print(end=" ")
m = m - 1 # decrementing m after each loop
for j in range(0, i + 1):
# printing full Triangle pyramid using stars
print("* ", end=' ')
print(" ")
输出:
Enter the number of rows: 10
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * * * *
代码-
rows = int(input("Enter the number of rows: "))
# It is used to print space
k = 2 * rows - 2
# Outer loop in reverse order
for i in range(rows, -1, -1):
# Inner loop will print the number of space.
for j in range(k, 0, -1):
print(end=" ")
k = k + 1
# This inner loop will print the number o stars
for j in range(0, i + 1):
print("*", end=" ")
print("")
输出:
* * * * * * * * * * *
* * * * * * * * * *
* * * * * * * * *
* * * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*
代码-
rows = int(input("Enter the number of rows: "))
# It is used to print the space
k = 2 * rows - 2
# Outer loop to print number of rows
for i in range(0, rows):
# Inner loop is used to print number of space
for j in range(0, k):
print(end=" ")
# Decrement in k after each iteration
k = k - 1
# This inner loop is used to print stars
for j in range(0, i + 1):
print("* ", end="")
print("")
# Downward triangle Pyramid
# It is used to print the space
k = rows - 2
# Output for downward triangle pyramid
for i in range(rows, -1, -1):
# inner loop will print the spaces
for j in range(k, 0, -1):
print(end=" ")
# Increment in k after each iteration
k = k + 1
# This inner loop will print number of stars
for j in range(0, i + 1):
print("* ", end="")
print("")
输出:
Enter the number of rows: 8
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*
代码-
rows = input("Enter the number of rows: ")
# Outer loop will print the number of rows
for i in range(0, rows):
# This inner loop will print the stars
for j in range(0, i + 1):
print("*", end=' ')
# Change line after each iteration
print(" ")
# For second pattern
for i in range(rows + 1, 0, -1):
for j in range(0, i - 1):
print("*", end=' ')
print(" ")
输出:
Enter the number of rows: 7
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*
代码-
rows = int(input("Enter the number of rows: "))
k = rows - 2
# This is used to print the downward pyramid
for i in range(rows, -1 , -1):
for j in range(k , 0 , -1):
print(end=" ")
k = k + 1
for j in range(0, i+1):
print("* " , end="")
print()
# This is used to print the upward pyramid
k = 2 * rows - 2
for i in range(0 , rows+1):
for j in range(0 , k):
print(end="")
k = k - 1
for j in range(0, i + 1):
print("* ", end="")
print()
输出:
Enter the number of rows: 5
* * * * * *
* * * * *
* * * *
* * *
* *
*
*
* *
* * *
* * * *
* * * * *
* * * * * *
我们已经讨论了使用for循环的基本金字塔图案。模式的概念取决于for循环的逻辑和正确用法。
在本节中,我们将介绍一些不同类型数字模式的程序。让我们一一理解以下模式。
代码-
rows = int(input("Enter the number of rows: "))
# Outer loop will print number of rows
for i in range(rows+1):
# Inner loop will print the value of i after each iteration
for j in range(i):
print(i, end=" ") # print number
# line after each row to display pattern correctly
print(" ")
输出:
Enter the number of rows: 5
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
说明-
在上面的代码中,我们根据行值打印了数字。第一行打印一个数字。接下来,在第二行中打印两个数字,在第三行中打印下三个数字,依此类推。在里面
代码-
rows = int(input("Enter the number of rows: "))
# This will print the rows
for i in range(1, rows+1):
# This will print number of column
for j in range(1, i + 1):
print(j, end=' ')
print("")
输出:
Enter the number of rows: 5
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
在上面的代码中,我们在内部for循环中打印了列值j。
代码-
rows = int(input("Enter the number of rows: 5"))
k = 0
# Reversed loop for downward inverted pattern
for i in range(rows, 0, -1):
# Increment in k after each iteration
k += 1
for j in range(1, i + 1):
print(k, end=' ')
print()
输出:
Enter the number of rows: 5
1 1 1 1 1
2 2 2 2
3 3 3
4 4
5
说明:
在上面的代码中,我们使用了反向循环来print向下倒置的金字塔,每次迭代后数量都会减少。
代码-
rows = int(input("Enter the number of rows: "))
# rows value assign to n variable
n = rows
# Download reversed loop
for i in range(rows, 0, -1):
for j in range(0, i):
# this will print the same number
print(n, end=' ')
print()
输出:
Enter the number of rows: 6
6 6 6 6 6 6
6 6 6 6 6
6 6 6 6
6 6 6
6 6
6
代码-
rows = int(input("Enter the number of rows: "))
# Downward loop for inverse loop
for i in range(rows, 0, -1):
n = i # assign value to n of i after each iteration
for j in range(0, i):
# print reduced value in each new line
print(n, end=' ')
print("\r")
输出:
Enter the number of rows: 6
6 6 6 6 6 6
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1
代码-
current_Number = 1
stop = 2
rows = 3 # Number of rows to print numbers
for i in range(rows):
for j in range(1, stop):
print(current_Number, end=' ')
current_Number += 1
print("")
stop += 2
输出:
1
2 3 4
5 6 7 8 9
代码-
rows = int(input("Enter the number of rows: "))
for i in range(0, rows + 1):
# inner loop for decrement in i values
for j in range(rows - i, 0, -1):
print(j, end=' ')
print()
输出:
Enter the number of rows: 6
6 5 4 3 2 1
5 4 3 2 1
4 3 2 1
3 2 1
2 1
1
代码-
rows = int(input("Enter the number of rows: "))
i = 1
# outer file loop to print number of rows
while i <= rows:
j = 1
# Check the column after each iteration
while j <= i:
# print odd values
print((i * 2 - 1), end=" ")
j = j + 1
i = i + 1
print()
输出:
Enter the number of rows: 5
1
3 3
5 5 5
7 7 7 7
9 9 9 9 9
代码-
rows = int(input("Enter the number of rows: "))
for i in range(1, rows + 1):
for j in range(1, rows + 1):
# Check condition if value of j is smaller or equal than
# the j then print i otherwise print j
if j <= i:
print(i, end=' ')
else:
print(j, end=' ')
print()
输出:
Enter the number of rows: 5
1 2 3 4 5
2 2 3 4 5
3 3 3 4 5
4 4 4 4 5
5 5 5 5 5
rows = int(input("Enter the number of rows: "))
for i in range(1, rows):
for j in range(1, i + 1):
# It prints multiplication or row and column
print(i * j, end=' ')
print()
输出:
Enter the number of rows: 8
1
2 4
3 6 9
4 8 12 16
5 10 15 20 25
6 12 18 24 30 36
7 14 21 28 35 42 49
在上一节中,我们讨论了所有基本数字模式。它将在Python进行强大的for循环命令。我们可以使用for循环的任何类型的模式。
我们知道,每个字母都有其自己的ASCII值,因此定义一个字符并将其print到屏幕上。让我们通过以下示例了解这些模式
代码-
print("The character pattern ")
asciiValue = 65 #ASCII value of A
for i in range(0, 5):
for j in range(0, i + 1):
# It will convert the ASCII value to the character
alphabate = chr(asciiValue)
print(alphabate, end=' ')
asciiValue += 1
print()
输出:
The character pattern
A
B C
D E F
G H I J
K L M N O
说明-
在上面的代码中,我们已将整数值65分配给asciiValue变量,该变量是ASCII值A。我们定义了for循环以print五行。在内部循环体内,我们使用char()函数将ASCII值转换为字符。它将print字母,并在每次迭代后增加asciiValue。
代码-
print("The character pattern ")
asciiValue = int(input("Enter the ASCII value to print pattern: "))
# User - define value
if (asciiValue >= 65 or asciiValue <=122):
for i in range(0, 5):
for j in range(0, i + 1):
# It will convert the ASCII value to the character
alphabate = chr(asciiValue)
print(alphabate, end=' ')
print()
else:
print("Enter the valid character value")
输出:
The character pattern
Enter the ASCII value to print pattern: 75
K
K K
K K K
K K K K
K K K K K
代码-
str1 = "JavaTpoint"
x = ""
for i in str1:
x += i
print(x)
输出:
J
Ja
Jav
Java
JavaT
JavaTp
JavaTpo
JavaTpoi
JavaTpoin
JavaTpoint
我们可以使用任何单词来print字符。
代码-
print("Print equilateral triangle Pyramid with characters ")
s = 5
asciiValue = 65
m = (2 * s) - 2
for i in range(0, s):
for j in range(0, m):
print(end=" ")
# Decreased the value of after each iteration
m = m - 1
for j in range(0, i + 1):
alphabate = chr(asciiValue)
print(alphabate, end=' ')
# Increase the ASCII number after each iteration
asciiValue += 1
print()
输出:
Print equilateral triangle Pyramid with characters
A
B C
D E F
G H I J
K L M N O
在本文中,我们讨论了所有基本模式程序。这些模式在面试中经常被问到,并且有助于理解Python for loop的概念。一旦获得了程序的逻辑,就可以使用Python循环print任何模式。