python基础（19-）

19

 

 

# 打开网址，程序之间通信，python均抽象为文件对待

# mode,默认只读r
f1 = open("name.txt","w") #默认同目录生成
f1.write("wzc")
f1.close()

f2 = open("name.txt")
print(f2.read())
f2.close()

f3 = open("name.txt","a")# 若为"w"，清除重写
f3.write("--18")
f3.close()

 20

f1 = open("name.txt")
for line in f1.readlines():
    print(line,end="")
"""
wzc--18
wqw--13
da--23
"""
print(f1.tell())#24
f1.close()

f2 = open("name.txt")
f2.read(2)#默认全部读取
print(f2.tell())#2,指针位置
f2.seek(0)
f2.seek(5,0)
#第一个参数表示偏移位置，第二个参数：0->从文件开头开始偏移
# 1->当前位置开始偏移；2->文件末尾开始偏移
print(f2.tell())# 0
f2.close() 

 21

try:
    print(1/0)
except ZeroDivisionError as e: #捕获特定异常
    print("error==>%s" %e)
    # error==>division by zero


try:
    print(1/0)
except Exception as e: #捕获全部异常
    print("error==>%s" %e)
    # error==>division by zero

try:
    raise NameError()
except NameError:
    print("name error!")

 

 

22

 

 

f2 = open("weapon.txt")
i = 1
for line in f2.readlines():
    if i%2 == 1:
        print(line.strip("\n"))
    i+=1import re
def find_item(hero):
    with open("three kingdom",encoding="GB18030") as f:
        data = f.read().replace("\n","")
        name_num = re.findall(hero,data)

    return len(name_num)

name_dict = {}
with open("name.txt") as f:
    for line in f.readlines():
        names = line.split("|")
        for n in names:
            name_num  = find_item(n)
            name_dict[n] = name_num

 

 

23

def func(a,b,c=3):
    print(a,b,c)
func(b=1,a=2)
# 2 1 3

def howlong(f,*other):
    print(1+len(other))

howlong("w",1,2,3,4)#5
howlong("w")#1
howlong()# error

 

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