Python – 矩阵中的垂直串联

给定一个字符串矩阵，执行字符串的按列连接，处理可变列表长度。

Input : [[“Gfg”, “good”], [“is”, “for”]]
Output : [‘Gfgis’, ‘goodfor’]
Explanation : Column wise concatenated Strings, “Gfg” concatenated with “is”, and so on.

Input : [[“Gfg”, “good”, “geeks”], [“is”, “for”, “best”]]
Output : [‘Gfgis’, ‘goodfor’, “geeksbest”]
Explanation : Column wise concatenated Strings, “Gfg” concatenated with “is”, and so on.

方法#1：使用循环

这是可以执行此任务的粗暴方式。在此，我们迭代所有列并执行连接。

Python3

# Python3 code to demonstrate working of 
# Vertical Concatenation in Matrix
# Using loop
  
# initializing lists
test_list = [["Gfg", "good"], ["is", "for"], ["Best"]]
  
# printing original list
print("The original list : " + str(test_list))
  
# using loop for iteration
res = []
N = 0
while N != len(test_list):
    temp = ''
    for idx in test_list:
          
        # checking for valid index / column
        try: temp = temp + idx[N]
        except IndexError: pass
    res.append(temp)
    N = N + 1
  
res = [ele for ele in res if ele]
  
# printing result 
print("List after column Concatenation : " + str(res))

输出

The original list : [['Gfg', 'good'], ['is', 'for'], ['Best']]
List after column Concatenation : ['GfgisBest', 'goodfor']

方法 #2：使用 join() + 列表理解 + zip_longest()

上述功能的组合可以用来解决这个问题。在此，我们使用 zip_longest 处理空索引值，并使用 join() 执行连接任务。列表理解驱动单行逻辑。

Python3

# Python3 code to demonstrate working of 
# Vertical Concatenation in Matrix
# Using join() + list comprehension + zip_longest()
from itertools import zip_longest
  
# initializing lists
test_list = [["Gfg", "good"], ["is", "for"], ["Best"]]
  
# printing original list
print("The original list : " + str(test_list))
  
# using join to concaternate, zip_longest filling values using 
# "fill"
res = ["".join(ele) for ele in zip_longest(*test_list, fillvalue ="")]
  
# printing result 
print("List after column Concatenation : " + str(res))

输出

The original list : [['Gfg', 'good'], ['is', 'for'], ['Best']]
List after column Concatenation : ['GfgisBest', 'goodfor']