# 單雙引號(hào)通用
msg = "Hello 數(shù)據(jù)科學(xué)家！"
path = r'C:\new_folder'  # 原始字符串避免轉(zhuǎn)義
# 切片操作 [start:end:step]
text = "Python超實(shí)用"
print(text[2:5])     # tho
print(text[::-1])    # 用實(shí)超nohtyP

names = ["張偉", "李娜", "王陽(yáng)"]
# 傳統(tǒng)方式（性能低）
full_str = names[0] + "," + names[1] + "," + names[2]
# 高效方式
print(",".join(names))  # 張偉,李娜,王陽(yáng)
# 現(xiàn)代方式（推薦）
print(f"獲獎(jiǎng)?wù)撸簕names[0]}、{names[1]}、{names[2]}")

# 拆分CSV數(shù)據(jù)
csv_data = "ID,Name,Salary\n101,張三,15000"
rows = csv_data.split('\n')
for row in rows:
    cols = row.split(',')
    print(cols)
# 重組URL路徑
folders = ['img','2024','logo.png']
print('/'.join(folders))  # img/2024/logo.png

log = "ERROR: File not found [code:404]"
# 定位關(guān)鍵信息
print(log.find("404"))    # 28
print("ERROR" in log)     # True
# 敏感信息脫敏
secure_log = log.replace("404", "XXX")
print(secure_log)  # ERROR: File not found [code:XXX]

# 1. %格式化（經(jīng)典）
print("溫度：%.1f°C" % 23.456)  # 溫度：23.5°C
# 2. str.format()（靈活）
print("坐標(biāo)：({x},{y})".format(x=120, y=89))
# 3. f-string（推薦）
name = "Alice"
print(f"歡迎{name.upper()}！積分：{1000*1.2:.0f}")

raw_text = "  Python數(shù)據(jù)分析  \t\n"

# 去空格
clean_text = raw_text.strip()  
print(clean_text)  # "Python數(shù)據(jù)分析"

# 大小寫(xiě)轉(zhuǎn)換
print(clean_text.upper())  # PYTHON數(shù)據(jù)分析
print(clean_text.lower())  # python數(shù)據(jù)分析

# 首字母大寫(xiě)
print("hello world".title())  # Hello World

def clean_text_data(text):
    """文本清洗標(biāo)準(zhǔn)化流程"""
    # 1. 去除首尾空白
    text = text.strip()  
    # 2. 轉(zhuǎn)換為小寫(xiě)
    text = text.lower()  
    # 3. 替換特殊字符
    text = text.replace('$', 'USD').replace('￥', 'CNY')
    # 4. 分割重組
    words = text.split()
    return ' '.join(words[:5])  # 保留前5個(gè)詞
raw_data = "  $19.99 限時(shí)優(yōu)惠 買(mǎi)一送一  "
print(clean_text_data(raw_data))  
# 輸出：usd19.99 限時(shí)優(yōu)惠 買(mǎi)一送一

>>> 'Hello' + ' ' + 'World' + '!'
'Hello World!'

>>> strlist = ['Hello', ' ', 'World', '!']
>>> ''.join(strlist)
'Hello World!'

>>> '{} {}!'.format('Hello', 'World')
'Hello World!'

>>> '%s %s!' % ('Hello', 'World')
'Hello World!'

>>> (
...     'Hello'
...     ' '
...     'World'
...     '!'
... )
'Hello World!'

>>> from string import Template
>>> s = Template('${s1} ${s2}!') 
>>> s.safe_substitute(s1='Hello',s2='World')
'Hello World!'

>>> from string import Template
>>> s = Template('${s1} ${s2} ${s3}!') 
>>> s.safe_substitute(s1='Hello',s2='World')
'Hello World ${s3}!'

>>> s1 = 'Hello'
>>> s2 = 'World'
>>> f'{s1} {s2}!'
'Hello World!'

#學(xué)習(xí)中遇到問(wèn)題沒(méi)人解答？小編創(chuàng)建了一個(gè)Python學(xué)習(xí)交流群：153708845
>>> def power(x):
...     return x*x
... 
>>> x = 5
>>> f'{x} * {x} = {power(x)}'
'5 * 5 = 25'