本文主要介绍 Hadoop 常用的命令。test命令用于检测文件或目录是否存在，判断文件或目录大小。-test -[defsz] <path> :
Answer various questions about <path>, with result via exit status.
-d return 0 if <path> is a
# 如何解决"WARN common.Util: Path /E:/hadoop/hadoop-2.2.0/data/namenode should be specified as a URI whose scheme and authority are 'null'. The uri we received was: /E:/hadoop/hadoop-2.2.0/data/namenode"错
三元表达式#三元表达式
name = 'alex'
name = 'egon'
res='SB' if name == 'alex'else 'shuai'
print(res)
#输出:shuaifor循环egg_list=[] #空列表
for i in range(100): #for循环
egg_list.append('egg%s' %i) #追加到egg_list空列表
